ORNL-TM-0907.txt

 

   

ORNI. TM 907

 

 

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MSRE DESIGN ANID OPERATIONS REPORT

  

FUEL‘HANDLINGAND PROCESSING PLANT :_'__ i

 

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PATENT CLEA
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 THE PUBLC 15 ANCE fismmso RELEA

PPROVED,-
A E PROCED
N lLE IN HE RECE!WNG SEC]{JIII?);S

_""uUflc[flus document cpntums :nformuhon of a prelmmary nature
- and was prepared primarily for mternol use at the Oak Ridge National -
'Luborofory lt is. sub;oc? to. tewston or _correction ond therefore does

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LEGAL NOTICE

This report was prepuud as an account of Govemmen! sponsored work. Neither lhe Umted States, -

nor the Commission, nor any person acting on behalf of the Commission:

- A, -Makes any worranty or representation, expressed or implied, with respect to the m:cumcy,'_' -
completoness, or usefulness of the information contained in this repert, or that the use of -

any information, apporatus, method, or process disclosed in this repori may not infringe
privately owned rights; or :
B. Assumes any liabilities with rcspec? to ibe use of, or for damages resulting from the use of
" any information, apparatus, methed, or process disclosed in this report.
As vsed in the above, “'person acting on behalf of the Commussion" includes any .mpfoyes or

contractor of the Commission, or smployae of such contractor, to the extent that such employee o

or contractor of the Commission, "or employes of such contractor prepares, disseminates, or

provides access to, any information pursuant to his omploymenf or contract with the Comm:ulon,

or his 0mp|oymem with such centracter,

 

 

 

 

 

 

 

 

 

 
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ORNL-TM-907

Contract No. W-7405-eng-26

MSRE DESIGN AND OPERATIONS REPORT

Part VII

FUEL HANDLING AND PROCESSING PLANT

R. B. Lindauer

 MAY 1965

OAK RIDGE NATIONAL LABORATORY
' Oak Ridge, Tennessee
~ operated by
UNION CARBIDE CORPORATION
for the
U.S. ATOMIC ENERGY COMMISSION

 
 

 

 

 

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PREFACE

This report is one of a series that describes the design and opera-

below.

ORNL-TM-728%
ORNL-TM-729

ORNL-TM-730%

ORNL-TM-731

ORNL~TM-732%

ORNL-TM-733

ORNL-~-TM-907%

' ORNL-TM-908%*

ORNL~TM~-909%%

ORNL-TM~910%

 ORNL-TM-911%%

C X%

‘tion of the Molten-Salt Reactor Experiment. All the reports are listed

MSRE Design and Operations Report, Part I, Descrip-
tion of Reactor Design, by R. C. Rovertson

MSRE Design and Operations Report, Part II, Nuclear
and Process Instrumentation, by J. R. Tallackson

MSRE Design and Operations Report, Part III, Nuclear
Analysis, by P. N. Haubenreich, J. R. Engel, B. E.
Prlnce, a.nd H. C. Claiborne

MSRE Design and Operations Report, Part IV, Chemistry
and Materials, by F. F. Blankenship and A. Taboada

MSRE Design and Operations Report, Part V, Reactor
Safety Analysis Report, by S. E. Beall, P. N.
Haubenreich, R. B. Lindauer, snd J. R. Tallackson

MSRE Design and Operations Report, Part VI, Opera-
ting Limits, by S. E. Beall and R. H. Guymon

MSRE Design and Operatioxis Report, Part VII, Fuel
Handling and Processing Plant, by R. B. Lindauer

MSRE Design and Operations Report, Part VIII, Op-

. erating Procedures, by R. H. Guymon

MSRE Design and Operations Report, Part IX, Safety
Procedures and Emergency Plans, by R. H. Guymon

MSRE Design and Operations Report, Part X, Mainte-
nance Equipment and Procedures, by E. C. Hise and
R. Blumberg

MSRE Design and Operations Report, Part XI, Test

-Progra.m, by R.: H. Guymon and P. N. Hau'benreich _
'MSRE Design and Operations Report, Part XIT, Lists:

Drawings, Specifications, Line Schedules, Instru—
mentation Tabula.tions (Vol. 1 and 2)

 

' *Issued.

i **These reports will be the la.st in the series to be published.

 
 

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CONTENTS

PREFACE +evecoecenosonsonnans eeeee Cesecsenane ceeeeen cereesens .o

1. INTRODUCTION «.vevecennsnssoanoosanssnssssasssesssnnnssnans

2. PROCESS DESCRIPTION eveuvevererocoooasens e ereaeeenenenes ..

¥ 2.1 H,-HF Treatment for Oxide Removal ....ceooeiccencncss .
2.1.1 SWBTY +.eevenennsns

2.1.2 Hydrofluorination ......eccieeeesss
2,1.3 NoF TTappifg eeeeeeeescevoacess Ceereeinenenas ..
2.1.4 Monitoring for Wabter sieeeeieiaccsscctscnscnsse
2.1.5 Off-Gas Handling .c.ceeecsscecses S
2.1.6 Iiquid Waste Disposal .e..eeeeeesons

2.2, Uranium RECOVETY +.veeeecscscrasarsssssasassnsanssosos

 

2.2.1 SUEATY eevverrvrorenanenns Ceraieereaen
2.2.2 Fluorination .......
2.2.3 NaF Trapping «......
2.2.4 UF¢ Absorption ........ teesasesessncssssansens .
2.2.5 Excess Fluorine Disposal e.ieeeeeeoss
2.2.6 Off-Gas Handling csecans cevssssccanss ceenannne .
2.2.7 Liquid Waste Disposal Gevetiraeeneesasnnessnns .
228 Waste Salt Handl:n.ng Cereeeesisastssenons ceeseae
. EQUIPMENT DESCRIPTION +sc:venerennonnsaseonsscessessnnnns
| 3.1 Pla.n‘b Layout .~.‘..‘.’..@.’;....;r..... ....... ieebsseasesens

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3.3 In-Cell EQUIDMENt wueeeeenvsesnetiennnrennassineeenns
3.3.1 Fuel Storage Ta.nk ...

3.3.3 Cold Trap . ..... '.,;7.'....'.......

3.3.4  EAPhOR POL «iesisnnssernnnsessnnnsocennionnsnes

- 3.3.5 Caustic Sf'ru'bber .......

_ _'3.3.6 :.Na.F Absorbers .

\g/ 37.3'.7 -Fluorine Dlsposal System e sassescnssssnanse cene
3.3.8 Cubicle Exhauster ....ceeeessescesscacsccsssoscs

)N “

 

3.2 Maintena-nce .."--;:.:-;-;-;L';;..';."..‘.';..‘...'..‘..--..';‘...,.

0 3.3.2 Nza‘F;,Trapf |

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3.4 Out-0f-Cell EQUIDPIENt ...ccevvevenrecernnanans P
3.4.1 Activated-Charcoal Trap sceeececeses
3.4.2 Flame Arrester scieeeeceececescascscsassasansss
3.4.3 Off-Gas Filters ..cecececcencee
3.4.5 HF Heater ...ccecevciisnicennnnnnann, ..
| 3.4.6 581t SBIDLET vueesenneenesnacsnnancoanernesnns
3.5 Electrical System .............. ......... '-
3.6. Helium Supply System .eceeeececensns . .
3.7 Instrumentation ....ceeececiorccionrecaonns ..
3.7.1 ThermocOUplesS ...coceveecscess .
3.7.2 Annunciators .. .............
3.8 Brine System .evceveeieciiaienennen .. ..... cese
 SAFETY ANALYSIS ........ e eeriereeeeenanns e ieeeieeeae.
4.1 Summary and Conclusions
4.2 Bases for Calculations ........cccevevnennn.
4.2.1 Diffusion FACEOT weeereeeecessseeeranneesnnn
4.,2.2 Air Contamination ...........
4.2.3 Activity in Salt ........eeee..
4.3 Gaseous Activity .......... cessvenas Cesesessscssesans

4.3.1 Activity Release from the Containment Stack ...
4.,3.1.1 Activity Released When Not

Processing cececescaccnvececcescns cie
4.3.1.2 Activity Released During Hx -HF
Treatment ...cvvsecccccncccascssnsvanne
4.3.1.3 Activity Released During Fluorina-
tion ..l...?.-.........ir ....... ;.._...‘.
4.3.1.,4 Activity Released by Equipment
Failm ....... '....O'.'.li....‘l.....‘. V
4,3.2 Activity Release to the Operating AT€s ..cuvinn
4.,3.2.1 Activity Released Through the
. : ROOfPlIJgS ------ bs s 000 ocoooo.o.-'.n:oo
4.3,2.2 Activity Released from the Absorber.
) CUbiCle ooroo-orooono --------- e s s s e «s®
4.3.2.3 Activity Released from the Cell .
Penetrations ....... cevesvesssscssnae .
4.3.2.4 Activity Released from the Salt
- Sampler .o--.o oooooo ® % 450200 8s e BB

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4.4 Penetrating Radiation eeenna et eeeeaari s eee e sanen
bobesl Normal Levels veeeeeeen... e,
, 4.4.1.1-operating AYCB vneeenesioresenannsanss
4.4.1,2 -Switch House ...... ceedsenaoserssantes
4,4,1.3 Spare Cell ....icieestcescroacccesanns
4.4.1.4 Decontemingtion Cell wu.eeveceseeevn..
4.4.1.5 Area Surrounding the Waste Cell ......
442 Unusual Radiation LeVels .e.eeeeeveeeecssssoees
4.4.2.1 TFrom Irradiated S8lt eecevveeeveencsss
bod.2.2 From Caustic Solution ......eeveeeses.
 4.4.2.3 From Radioactive GBS virreriieneniines
OPERATING PROCEDURES ¢..v.vveenss e aececaesacietneateona .
NOMENCLATUTE v .o vs e v vnt e s e e tmaes e eaeeeeesiinenennnnnn
5.1 Ho=HF Treabment .oe.eveeeeceresccanensacossssasonaness
5llSWmmm$T%tnq{ ...... e e reedrrenenns
©5,1.1,1 Close System ....... Ceeeeeee e R
5.1. l 2 Apply Pressure and Test ...... . .
- 5.1.2 Absorber and Instrument Cub:.cle Preparatlon coe
5.1.2.1 Prepa.re and Test Piping in Cubicle .
5.1,2.2 Leak Test AbsOTber Cubicle Jee.ees....
_ 2.1.2.3 Leak Test Instrument Cubicle .........
'5.1.3 System Preparat:.on et ereraner e .o
5.1.3.1 'Cha.rge Caustic Scrubber ;'.”";'. eeiiidl .
| ‘5.’17.'3.72,7-;Purge FST and Gas Plping ceseseenannee
©5.1,3.3 Transfer Salt Batch to FST ...;.;,.,;.'
'5.1.3.4 Adjust Purge Gas Flows ;;;;:;, ....... .
5,1.3.5 i:-'AdJust Temperature s ........ :
5,1.3.6 "":Check Instrumentation i
. 5., 3.7JfStart Up Cold Trap SYStem s...eveesscs
:35.1;4.:Treatment_r.......................;.;;,...,.,;;3'
5.1.4.1 Sample Salt .iseeeiieiiennennesconnnn
5.1.4.2 Start Gas FLOWS veeeveceerereeesnenee
511043 TPEEL SBIY vareinriieeaiiivereneiienns
5.1.4.4 Iron ReQUCHION eeueeseeen.n. Cersseieas
5.1.4.5 Shutdown System eeceveees

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5.2

viii

515 Liquid Waste Disposal ...... csecssennsnnmaie ces
5.1.5.1 Radiation Level Monitoring ......... e
- 5.1.5.2 Liquid Waste Sampling ....ccevceeee cee
5.1.5.3 Liquid Waste Dilution .e.ce.civeceaess

5.1.5.4 Transfer to Melton Valley Waste
Station .c....oveveenn cecevesaasnas ces
Uranium RECOVETY «e.verecaccarnss v ....... .
5.2.1 SystemLea.kTest ............ seciseenaes
5.2.1.1 Close System...._... ...... .

5.2.1.2 Apply Pressure and Test veeveerrencana

5.2.2 Absorber and Instriment Cubicle Preparation ‘oo

5.2.2.1 Install Absorbers ........ T
5.2.2.2 Leak Test Absorber Pip:l.ng .
5.2.2.3 Leak Test Abgorber Cubicle ........eee
~ 5.2.3 System Preparatn.on ...................... eeseas
5.2.3.1 Cha.rge Caust:n.c Scrubber.... .- ..... csene
5.2.3.2 Purge FST and Gas Piping ........ e
5.2.3.3 Transfer Salt Batch to FST ..... P
5.2.3.4 Adjust P\irge Gas Flows seeeceeess
5.2.3.5 Adjust Temperatures ................. .
5.2.3.6 Check Instrumentation ......eecceuevee
5.2.3.7 Prepare Fluorine Dlsposal System roveas
5.2.4 Fluorine_cdnditioning Cressecacsscstsenns cecsan
5.2.4.1 Sample Caustic Solution .c.ceceecscne .o
5.2.4.2 Adjust Tempefatures cesscscnns csasrens
5.2.4.3 Start 502 FLOW ..iecveceninnncndosscss

5.2.4.4 Start Fluorine and Helium Flows ......

5.2.4.5 Increase Fluorine Concentration
to 50% .7.................. ..... *» &P ¢ 0N

5.2.4.6 Increase Fluorine Concentration
to 75% .I.C..........‘..l.....‘..."..’.'..

5.2.4.7 Increase Fluorine Concentration
tO 1%% -.--; ------- e s s easnsesersRBEREe

5.2.4.8 Shutdown SYStem «...ce.eeeens. e

 

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D¢2.5 Fluorination ..ceeeceseeeeseeescencssnnnes csene

5.2.5.1 ©Start Fluorine Flow ........cc... cesna

5.2.5.2 Fluorinate ....... cesietiaanns serevess

5.2.5.3 Sample Salt se.cv..n. esessessensans .

5.2.5.4 Shutdown System .......... eseeen ceess

5.2.6 Waste Salt Disposal .....eoenveveenne cerasesnna
5.2.7 Absorber Removal .e...veceiirncesanocanadnns “os
- 5.2.7.1 Check Cubicle ........ cerrieirsiecnans
5.2.7.2 Open Cubicle ...evevvensnannesnasss

5.2.7.3 Remove ADSOTDETS ...ueeeeeeeoeennnns .o

5.2.8 Tiquid Waste DLEPOSALl o.verenveennenns e cee
5.2.8.1 Rediation Level Monitoring ......... .o

5.2.8.2 Liquid Waste Sampling ......ceeceece.. .

5.2.8.3 ILiquid Waste Dilution ...... eraeene .o

5.2.8.4 Transfer to Melton Valley Waste

Station ...... Secrsesssrrsessesesanans

5.3 Equipment Decontamingation eee.eveieeeesecesacecansenns

5.3.1 Summary ..... ceecesescssnssasassannans tesesesuns

5.3.2 Preparation for Decontamination ...... ceessenas

5.3.2.1 8alt Flushing ...... Cerracsenccscnsnns

5.3.2.2 RemOVe NaF TTBD onuuvvvneernnnnnnnnnns

5.3.2.3 Radiation SUrvey ..i.ieeveeeececancessa

5.3.2.4 Liquid Waste Line .......cvvveveeneene

- 5.3.3 Oxalate Treatment .......cc..0e0u.es Cesssecae .o
- 5.3.3.1 OxalateCharging Ceeeeesecasecaccannns
"5;3.3;2-;Ofiéléte_Treatment Crereans e

, 5.3.3. 3i'Radiatioh Survéy teesreenitevnsassruya
5.3.4 Alkaline Peroxide Tartrate Treatment Ceevieeeen
“ 5341s&mmn%mam.“”"”“g“n;;

) 5.3.4.2 Radiation Burvey ............. '...;....
. 5.3.5 Nitric Acid—Aluminum Nitrate Trestment ....ess.
| ' 5.3.5.1 Solution Charging Ceteitetetettscannns
5.3.5. 2 Nitrate Treatment ......}...7 ........ .o

5.3.5.3 Radiation SUTrvVeY ..eeeeveeeeocesccares

References ....ce0veeveeeen Seesecrscsvsencessssssnssatescans

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1

MSRE DESIGN AND OPERATIONS REPORT

Part VIT
FUEL HANDLING AND PROCESSING PLANT

" R. B. Lindauer
1. INTRODUCTION

TheVMBRE'ffiel-processifig°system.was'deSigned to remove oxides from
the fuel, flush, and coolant salts and to_recover uranium from fuel and
flush salts. The H24HF tfeatment.fbr oxide removal will be used whenever
it is suspected that oxide contemination has occurred. The flush salt
will be treated after the initial flushing and shakedown operations and
after the system has been opened for meintenance. Fuel salt or coolant
salt could become conteminated through & leak in the system or difficul-
ties with the helium blanket system. Treatment of the coolant salt will
require salt transfer by means of transfer cans or a temporary heated

line. A decay time of at least four days will be required for evolution

of xenon before treatment of a fully irradiated fuel batch, since the

fuel-processing tank is not vented through the large charcoal beds.
Uranium will be recovered by volatilization with fluorine from flush

 

and fuel salts befbre'changing'frqm 35% enriched to highly enriched ura-

- nium and at the end of the programfbefore dlscardlng the salt to waste.
At the present time there 1s no developed process for recovery of the
.leF and BeFa. A.decay time of 30 d&ys for flush salt and at 1east 90
1days fOr a fully 1rrad1ated fuel batch is de81rable to reduce the amount

:'of volatlle flSSlon products.a'_,f*

 
 

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2. TPROCESS DESCRIPTION

2.1 H,-HF Treatment for Oxide Removal

2.1.1 Summary

Moisture or oxygen inleakage into the reactor salt system or use of
helium cover gas containing moisture or oxygen could cause oxide accumu-
lation in the salt and, eventually, precipitation of solids. In the flush
or coolant salts, the precipitated solid would be BeO, which has a solu-
bility of approximately 275 ppm at 1200°F (see Fig. 2.1). If the flush
salt is contaminated with fuel salt up to.approximately 0.01 mole of zir-
conium per kg of salt (~1% fuel in flush salt), there would be insuffi-
cient zirconium present to exceed the solubility of Zr0; at 1112°F, and

¢)

‘any precipitate would be BeO. Above this zirconium concentration, ex-
ceeding the solubility limit would cause Zr0, precipitation. The effect
- of 10% contamination of the flush salt with fuel salt is shown in Fig.
2.1. The solubility of Zr0z varies with temperature and zirconium con-
centration as shown in Figs. 2.1 and 2.2. The dashed lines in Fig. 2.2
indicate extrapolation of date above 0.5 mole of Zr“t per kg of salt.
The oxide solubility in fuel salt is probably not as high as this extrapo-
lation indicates. .

Zirconium tetrafluoride was added to the erlrsalt as an oxygen
getter to prevent small amounts of oxygen from causing uranium precipi-
tation. Table 2.1 shows the maximum amount of oxide that can be tolerated -
before zirconium and uranium oxides precipitate in flush salt containing T
small amounts of fuel salt. When U0, starts to precipitate,_ZfOz will v |
continue to precipitate. The ratio of zirconium to uranium in the pre-
cipitate will be 5:1 at 932°F or 3.8:1 at 1112°F. These ratios will be
slightly lower if the amount of fuel salt present is large. With pure
fuel salt the ratio is l.5:1, and more than 14,000 ppm of oxide will be
required before uranium will precipitate. | -

Operation of the reactor with precipitated solids is to be avoided.
Even operetion with high concentrations of dissolved oxides could result

in collection of oxides on relatively cold surfaces, such as the tubes &aj

 

 
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LIQUIDUS //

TEMPERATURE

 

OXIDE SOLUBILITY (ppm)

 

3

 

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FLUSH SALT WITH

 

 

 

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.. Fig. 2.1,
- _perature,

2

i)}

700

800 900 1000 1100 1200 300 1400
. TEMPERATURE (°F) ' '

. Solubility of Oxides ‘in ;FluSh Salt as a Function of Tem-

 
 

 

OXIDE SOLUBILITY (ppm)

Fig. 2.2.
Concentration.

 

ORNL-DWG 65-2506

/

1112°F
BeO
SOLUBILITY

FUEL SALT C

0.2 o4 06 08 10 w2 1.4
Zr CONCENTRATION (moles/kg) -

Solubility of Oxides in Salts as a Function of Zirconium

 

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Teble 2.1. Oxide Capacity of Molten Salt

 

Oxide Capacity (ppm)

 

Tuel Salt

 

 

in At 932°F | At 1112°F
Flu?;)Salt Before Before Before Before
Zirconium Uranium . Zirconium Uranium
Precipitation Precipitation Precipitation Precipitation

/2 4.5 90.5 264 o

1 53.5 88.5 199 o™
11/2 46 | 104 174 284

2 39 : 122 149 299

3 33 176 129 | 364

4 29.2 : 241 118 bl

5 27 .4 - 315 : 112 528
Fuel salt C >33 - - >14,000 : >320° >14, 000

 

aInsui‘flclent zirconium and uranium to prec1p1tate. At greater
than 175 ppm of ox1de, BeO will prec1p1tate.

in the heat exchanger and - the ‘access nozzle on the reactor vessel. At

present the ox1de concentratlon cannot be measured with sufficient ac-

~curacy for us to kmow whether the salt is saturated. Until the analytical

methods are 1mproved, the oxide concentration will be kept low by treat-
ing the salt at regular 1ntervals and when there has been an opportunity
for eon31derable moisture. to enter the reactor system. Moisture could

enter if heljum of hlgh.m01sture content were'used for cover gas or if

. the systemuwere open to the atmosphere during long periods of maintenance.

| Oxides will be- removed by treatlng the fuel or flush'salt in the
fuel storage tank (see Flg. 2. 3)’W1th a mixture of Hp and HF gas. In

‘the treatment process, HF‘Wlll react‘w1th the oxide to. form the fluoride

'._and.water, which will be evolved along with the hydrogen and excess HF.

The Hz will prevent excessive corrosion of the INOR-8 structural material

- by maintaining a reduclng condltlon in the salt. The-gaseS'will'pass'
"fithrough an NaF bed fbr decontamlnatlon before cold trapping for water
”sdeterminatlon. The gas stream'w1ll then pass through a caustic scrubber

for neutralization of the HF. The hydrogen will go to the off-gas systemr

 
 

 

 

   
    
 

 

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SALT 200°F Nof ABSORBERS IN CUBICLE
SAMPLER % ,
' e == —/
SALT
, .
T:‘_‘: e e —— —_—— - e
FUEL PROCESSING CELL : o
H,-HF OR F, , : o
o |
SALT T0 OR o ! L
) ACTIVATED
AND FLUSH TANKS ' 1 | eriarcoar
: ' 1 | TRaP
' i
WASTE ! FUEL | ' '
SALT | STORAGE | FLUORINE
TANK | | TANK | DISPOSAL| | .
= ! { SYSTEM || -
P ! + ! N | }aesoLute
i 1 | - : FILTER
\\_} ’ . -
' \ TO VENT
) CAUSTIC
N:{."’;go NEUTRALIZER H SYSTEM

Fig. 2.3. MSRE Fuel-Processing System.

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- The treatment will be terminated when water is no longer detected in the

off-gas stream. A final sfierging with bydrogen will remove dissolved HF
and FeFs.

2.1.2 gydrofluorlnatlon |

 

Hydrogen fluoride will be obtained in 100-1b cyllnders.r One cylinder

will-provade sufficient HF for 92 hr of processing at a flow rate of 9

Liters/min (Ho:¥F = 10:1). The HF cylinder will be partially submerged

.Jln a water bath heated with low-pressure steam to provide sufficient pres-

gsure for the required flow rate. Since heating of the cylinders above

125°F is not recommended, there is a pressure alarm-on the exit gas set

at 25 psig. The HF gas will pass through an electric heater to raise .the
temperature above 160°F and reduce the molecular weight to 20 for accurate

flow metering. The hydrogen flow will be started before the HF flow to
minimize corrosion. The hydrogen flow rate will be set at the rotameter

at the gas supply'station:weet'of the building. The hydrogen fluoride

flow rate will be regulated by the controller on the panelboard in the

high-bay area. The salt backup prevention valve must be closed with the
manual switch until flow is started, at which time the differential pres-
sure switch will maintaintthe,valve in the closed position unless the
tank pressure exceeds the Hé-HFVPressure.

From exper1ence*w1th an Inconel vessel. in the Englneerlng Test Loop,
corrosion is expected to be negllglble after the surface is depleted of
chromlum.and iron. The equllibrlum amount of nlckel in solutlon'w1th a

© 10:1 ratio of Hz to HF is less than 1 ppm. -

The off-gas stream 1eav1ng ‘the fuel storage tank Wlll con31st of

_bhydrogen, water, excess hydrogen fluorlde, and helium. Vblatlllzatlon

- of fission and corrosion products is expected to be much. lcwer than dur-

" 1ng fluorination because of the reduclng effect of the hydrogen. Fission
":fproducts that are partially volatilized as fluorldes durlng fluorlnatlon,

i-such &s ruthenium,. nldblum, and antlmony, are expected to exlst in the

tfnmtalllc state. Any chromlum.ln the salt from corrosion is expected to

| ;be in the nonvolatile +2 or +3 valence state.~,Theeoff—gas stream will

pass through a heated line to the NaF trap. The line will be heated to
200°F to prevent condensation of H,O-HF.

 
 

 

Since corrosion and fission-product volatilization will not be severe
during Ho-HF treatment, the salt will be maintained at 1112 # 20°F, which
is approximately 200°F higher than during fluorination. At the higher
temperature the conversion of oxide to water will be mofe rapid.

The hydrogen fluoride flow will be stopped when no more vater is de-
tected in the off-gas stream. The salt temperature will then be increased
to 1300 % 20°F and the hydrogen flow will be continued to remove dissolved
hydrogen fluoride and to reduce the amount.of FeFz in solution. It should
be possible to reduce the dissolved iron to the 200-ppm level obtained in
the salt production operation. Any iron returned to the reactor system
will cause corrosion by attacking any exposed chromium. When the salt
samples show that further reduction of iron is not practica1, the hydrogen
flow will be stopped, and the salt will be sparged with nitrogen for 8 hr
to purge the gas space of hydrogen. '

2.1.3 NaF Trapping |
A remotely removeble NaF bed is provided in the fuel-processing cell

to remove small amounts of volatilized fission or corrosion products from
the off-gas stream. The trap will be maintained at 750°F to prevent ad-
sorption of HF. Since the vapor pressure of HF over NaF is 1 atm at 532°F,
the trap could be operated at a somewhat lower temperature, but 750°F will
be required to prevent UFg adsorption during fluorination (see Sect. 2.2.3),

and this temperature was selected for both operations.

2.1.4 Monitoring for Water

The removal of oxides from the salt will be followed by observing the
volume of water and HF cold trapped from the off-gas stream; The entire
- gas stream, consisting of helium,'hydrogen, water vapor, and excess hydro-
gen fluoride, will pass through a cold trap. The temperature can be
varied between O and 40°F. Since the ratio of water to hydrogen fluoride
in the off-gas stream leaving the fuel storage tank will be a function of
the oxide content of the salt,l,the HF utilization versus the oxide con-
tent can be calculated ffomAthis relationship, as shown in Fig. 2.4. The

solubility of oxide in fuel salt is high, and therefore the equilibrium

O

(n

Wi

[\

»

 
N

ORNL-DWG 65-2507

 

1000 , -
- - . - I_PHao !

| [07] (moles/kg) = Qo o2 (otm)

- S HR,

- 6.0 x10°5 FOR PURE FLUSH SALT

+~ WHER = . _
€ E Qo 1.47 %1074 FOR FLUSH SALT + 5% FUEL SALT

| TEMPERATURE = {{{2°F ' I /

| H,-TO-HF RATIO = 10:1

 

 

 

 

 

 

:500

 

 

 

 

L.

200

 

100

 

 

 

 

 

50

 

 

 

 

OXIDE CONTENT (ppm)

 

 

 

 

 

10

 

 

 

 

 

 

#
O

 

o)

 

 

 

 

 

 

 

 

 

 

o 20 40 60 80 . 100
.0 UF UTILIZATION (%) o

W/ ~ Fig. 2.4. HF Utilization as a Function of Oxide Content.

 

 
 

 

 

o

10 | ;

HF-to-Hz0 ratio in the off-gas will be high (low HF utilization). This
could result in long treatment times for removing large quantities of
oxide from fuel salt. Since accurate solubility date for the fuel salt
are still being measured, the utilization_éurve for ffiel_salt is not
shown. | _ | .:

The amount of.water and hydrogen fluoride that will be carried with
the hydrogen-helium off-gas stream from the trap can be calculated from

the vapor pressure of water and HF over the condensed liQuid. By means

¢ ]

of a material balance, the amount of condensed liquid to be expected was
calculated as a function of the oxide content. The amount of condensgd .
liquid for a cold trap temperature of O°F and an Hé-to-HF,ratio of 10:1
is shown in Fig. 2.5. The condensate volumes in Fig. 2.5 do not include
the untrapped water, which should amount to less than 2% and can be ig-
nored. -If melts containing very large amounts of oxide are being treated,
the HF utilization at the start will be slightly higher than shown due
to Zr(OH), formation, but the curve shown should be reasonebly accurate
at the oxide levels expected. |

The condensed HF-H>0 will be collected in a small pot that will
siphon automatically when full. ZEach siphoning will remove approximately
55 cc. The number of siphonings will be recorded on a temperature re-
corder that will detect the cold liquid as it passes through the siphon
tube to the caustic scrubber. The siphon pot and cold trap will be cooled
by circulating brine.

™

2.1.5 0Off-Gas Handling

The hydrogen fluoride will be neutralized in a static caustic serubber | s :
tank. Hydrogen and helium from the scrubber will pass through an activated-
charcoal trap and a flame arrester before entering the cell ventilation
duct. The cell ventilation air will pass through an absolute filter,'lo-
cated in the spare cell, before going to the main filteré and stack. As
mentioned before, little activity is expected in the offégas stream during
H,-HF treatment. | - '

Since the fluorine disposal system will not be used during Hp-HF
treatment but will still be connected to the scrubber inlet line, the ‘uwj

-,

 
%

11

 

ORNL ~-DWG 65-2508

180
T T )

CONDENSATE 'VOLUME = 2XI2E REMOVED (ppm) x 4.5x10° g OF SALT X 100
_ 7 % WATER IN CONDENSATE x 40°%

160 I—— COLD TRAP TEMPERATURE, O°F — ; ' /

Ha-TO-HF RATIO, 10:4 /

140 |— 7 : /

 

 

¥

w)

 

 

{20 -

t00 | — /

 

 

 

60

 

OXIDE REMOVED FROM FLUSH SALT (ppm}
®
o

 

40

 

 

 

 

 

 

 

 

 

 

 

 

 

2 | :
0 : : — ' ' -
0 200 - 400 - 600 800 1000 - 4200 - - 4400 -
: o VOFUME OF:CONDENS_ATE {ce) )
‘zg_:__f:‘Fig'.'_2'.5. Condehsé.te 'Vcilmne'as a Function of Amount of Oxide Re-
" moved from Flush Salt. S o o

 

'y

 
 

 

12

system must be purged to prevent diffusion and condensation of H,O-HF in
thé disposal system. This will be done by connecting Nz cylinders at the
502 cylinder manifold. As an additional precaution, the S0, preheater
should be heated, because the stainless steel preheater would be éspecia.lly
subject to corrosion by the wet HF.

2,1.6 Liguid Waste D:LSposal

‘The caustic scrubber w111 be charged with 1300 liters of 2 M KOH
prepared by dilution of a 45% KOH solution. Three 115-gal batches of
2 M (10%) KOH will be prepared in a portsble mix tank in the high-bay
area and charged through a line rpxr'rovided with a manual valve and a check
velve. Dilution to 27 M will be required because of the possibility of
gel formation in KF solutions of greater than 2 M. | |

At 9.1-liters/min HF flow, the KOH will have to be replaced every
4 days when the final concentration is 0.35 M. It will, th'ereforre, be
necessary to jet the KOH solution to the' liquid‘ waste tank and replace
it with fresh caustic when a iOO-lb HF cylinder has been consumed.

2.2 Uranium Recovery

2.2.1 Summary
The fuel or flush salt should be allowed to decay as long as possible

before fluorination to minimize the discharge of the volatile fission-
product fluorides that will be foxrmed by the oxidizing action of the
fluorine. The most important volatile activities are iodiné, tellurium,
niobium, ruthenium, and antimony, and large fractioné“are" expected to
plate out on metal surfaces of the equlpment.

After decay, the salt batch will be fluorinated in the fuel stora,ge
tank. The off-gas containing UF4, excess fluorine, and volatile activity
will pass through a high-temperature NaF trap for decontamination and
chromium removal before absorption on low-temperature NaF absorbers. Ex-
cess fluorine will be reacted with SOz to prevent damage to the Fiberglas
filters. Before filtration the off-gas will be further decontaminated by
passage through a caustic scrubber and an activated charcoal bed.

4

w,

 

 
 

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13

The absorbers will_bertransported to the Volatility Pilot Plant where
they will be desorbed and the UFg cold trapped and collected in product

cylinders.

2.2.2 Fluorination

Uranium will be recovered from the molten salt by sparging with fluo-
rine to convert the UF4,tojvolatile UFg. The fluorine will be diluted
with an equal volume of helium when fluorine is detected in the off-gas
stream to reduce the number of times the fluorine trailer and the caustic
in the scrubber must be changed. This should have little effect on the
overall processing time, sinee utilization is expected to be low after
most of the uranium has been volatilized. A total gas flow of about 100
liters/min should provide good agitation.' The salt sample line will be
purged with helium.during fluorination to prevent UFg diffusion and will
be heated to prevent condensation. The temperature of the melt will be
maintained as low as practical (FQO to 30°F above the liquidus of 813°F)
to keep corrosion and fission-product volatilization to a minimum. Boil-
ing points of some volatlle fluorldes are listed in Table 2.2, While all
the iodine and much of the tellurlum is expected to volatilize, only a
small fraction of the ruthenlum, z1rcon1um, niobium, and antimony should
leave the salt. The heaters on the upper half and top of the tank will
not be used during fluorlnatlon to reduce salt entralnment, but they will
be turned on after fluorlnatlon to melt down splatter and condensatlon.

There will be an 1n1t1al 1nduet10n perlod before evolutlon of 10)

beglns. The extent of thls perlod Wlll depend on the amount ‘of uranium

iln the salt and the degree of agltatlon of the salt._ A.mlnlmum.of 0.5
”7~fmole of fluorlne per mole of uranlum.W1ll be requlred to convert all the
"~1-UF4 to UF5. After thls, UFg will begln to fbrm and be evolved. At 100

77 ”1iters/m1n of fluorlne, UF6 evolutlon can begin about 2 hr after ther

B start of fluorlnatlon. Slnce the vapor space between the salt and the
- first absorber is thOO llters, another 15 min will probably be requlred

'befbre absorptlon beglns."1ffi.

Volatllity Pllot Plant data show that essentlally no fluorlne is

evolved until at least 1 mole of fluorine per mole of uranium has been

 
 

 

14

Table 2.2. Boiling Points of
Fluoride Salts

 

Boiling Temperature

 

CF, L -198

TeFe -38 :
 IFy 39 (sublime)

MoFg 95 o
. UFg , 130

TeoFi 0 138

PuFg ' 144

IFs 212 -

CrFs 243

SbF's5 300

MoF's - 440

NbFs 44ty

RuF's 518

TeF, 543

SbF4 554

CrF, 567

RuF, 585 _

ZrF, 1658 (sublime) .

CrFi, ~2000

 

added or the system has operated 4 hr at 100 1iters/min. However, until
more is known about the sparging efficiency and the effect of the fuel
storage tank geometry and salt composition, the fluorine disposalrsystém
should be put in operation 2 hr after the start of fluorine flow with

- sufficient SO0 to react with 50 liters of fluorine per minute,'

Evolution of UFg will be followed by means of the absorber tempera~

tures. Fluorine breakthrough should be detectable by temperature rise
in the fluorine reactor. When fluorine breakthrdugh is detected, the
fluorineinW'will be reduced to one-half and an equal flow of helium
will be started. This will maintain the necessary degree of mixing

- while providing sufficient fluorine to prevent the back reaction
-'2UF6—’2UF5+F2 .

Corrosion can consume as much as 9 liters of fluorine per_minute (0.5
mil/hr). |

B

 
 

 

»

A

V&)

"

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"

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15

" With the 35%-enriched ura.nimn fuel: salt, it will be necessary to re-
place the absorbers two t:unes.f Before this can be done, the salt must be
spa.rged with helium for 2 hr to remove dissolved UFg and fluorine and to
purge the gas space of UFg. At the end of the fluorination, when UFg is
no longer detected in the gas stream entering the absorbers, the fluorine
flow will be stopped and the batch sparged with nitrogexi for 2 hr.  After
sparging for absorber changes and at the end of fluorination, the salt
will be sampled to check on the uranium removal.

It will be necessary ';to:i"eplace the fluorine trailer every 2 hr at
a fluorine flow rate of 100 liters/min or every 4 hr with one-half flow.
There is sufficient space at the gas supply station to have only one
trailer connected at a time. Additional trailers will be at the site,
however, so downtine shouid not be 1ong -

Corrosion will be much more severe _under the strongly oxidizing con-
ditions of fluor:.ne.‘tlon tha,n dur:mg the HZ-HF treatment. A corrosion
rate of 0.5 m:Ll/hr was exper:_Lenced in the Volatility Pilot Plant in a
nickel vessel. Fluorination of the high-ux"animn-content salt (fuel salt
¢) may take as long as 24 h:r, but recovery of smll a.mounts of uranium
from the flush salt and ura.m.mn recovery from hlghly enr:.ohed fuel should
require much less time. A 24-hr fluorination would cause an average cor-
rosion of approkiinat_eiy""B%: of the fuel ,js_torage ta.nk,wallrat 0.5 mil/hr.
Corrosion of the fuel st’o'rage tank may ‘be somewhat less because of the

smaller surface-to—volume ra.t:.o, the use of dilute fluorlne » and the

lower fluorination tenlperature" a.lso, ‘corrosion tests- :mdn.ca.te that INOR—S’

may be more corros:.on resistant than nickel.

. _2 2 3. NaF Tra.m%

7 The NaF bed will be 1mportant dur:mg fluorn.natlon for uranium re-

covery because of - 'bhe greater volatlllza.tlon of f:Lss:Lon and corrosn.on

"'f""products then during oxlde remorv'a.l. The bed will- a.ga:.n be maintained .

at 750°F, that is, above the decomposnlon ‘temperature of .the UFg-2NaF

p com_plex ('702°F at 1000 mm) Any volatilized PuFg will: absor'b on the
. NaF and provide sepa.ra.tlon from the uranium. Sodiwm fluoride at 750°F

will remove greater than 90% of the nicbium and ruthenium from the fluo-

rinator off-gas stream, and these will be the principal activities that

 
 

16

-could cause product contemination. More iodine and tellurium will vola-
~tilize, but they will not absorb on hot or cold NaF. Essentially all the
chromium fluoride will be absorbed. Chromium is troublesome not only
because of the gamma activity of the 5lcr formed by neutron activation
but also because of the inactive chromium that will collect in valves

and small lines and cause plugging and seat leakage. All piping to and
from the NaF bed rust be heated to above 200°F to prevent UFg condensa-
tion. Table 2.3 shows the expected behavior of the volatile fluorides
on NaF.

Table 2.3. = Fluoride Absorption on NoF

 

 

Absorption . Absorption -

Fluoride at 750°F at 200°F

| (Na¥ Trap) (UF¢ Absorbers)
Todine No No

Tellurium No No

Molybdenum No Partial breakthrough
Uranium No Yes = ' :
Neptunium No Yes

Technetium ~ No Yes SR
Zirconium Yes Less than at 750°F
Niobium Yes Less than at '750°F
Antimony Yes Less than at 750°F
Ruthenium Yes Less than at 750°F
Plutonium ~Yes  Less than at 750°F
Chromium Yes Less than at 750°F

 

2.2.4 UFg Absorption
The decontaminated UFg gas from the 750°F NaF bed will flow to five

NaF absorbers in series, which are located in a sealed cubicle in the
high-bay area. These absorbers will be cooled with air, as _required, to
prevent uranium loss. At 300°F the vapor pressure 6f UFg over the UFg-2NaF
complex will be O.1 mm, and uranium losses will be significant ,(0.132 g

of U per minute with & flow of 100 liters/min). The capacity of NaF for
UFe veries inversely with the temperature, since the more rapid reaction

‘at higher temperatures inhibits penetration of the UF¢ by sealing off - .

"

 
n

»

H

¥

¥

i)

17

the external pores with UFg+<2NaF.2 To obtain maximum capacity the cool-

ing air should therefore be turned on as soon as a temperature rise is

indicated. .Also,'with low fluorine concentration at elevated tempera-

tures there could be a reduction of UFg+2NaF to UF5+2NaF, which would

remain with the NaF when the UFg was desorbed from the NaF. The loading
of the absorbers can be followed by bed temperatures, and the air can be
adjusted as required. The air will be discharged to the cell by a small

- blower in the cell..

-,Alpha?activity.monitors;in the cubicle and in the cell and vessel

off-gas streams willVbe used to detect leaks of UFg. In the event of a
"leak in the absorber cubicle, the fluorine flow would be stopped and the

cubicle would be purged with air and opened for repairs. The location
of the leak should be detectable either visually or with an alpha probe.

When fluorination has been completed, the.absorbers.fiill be discon-
nected and sent to the Volatility Pilot Plant for desorption and cold
trapping of the UFg. The maximum radiation level at contact will be less
than 100 mr/hr. When processing fuel salts A or C, which have higher
urenium molerity than salt B, it will be necessary to stop fluorination
when the absorbers are loaded and,replaee the absorbers as noted above.
This will require a complete purging of the system to get all UFg out
of the connecting piping. B

2. 2 5 Excess Fluorlne Disposal

Since an average eff1c1ency of less. than 25% is expected during .

rafluorinatlon, there w1ll be a- large excess of fluorine. If this fluorine
”fwere allcwed to flow through the off-gas filters, damage to the Fiberglas
ifmight result with release of any'accumulated act1v1ty.. To prevent this,

Vthe excess fluorine w1ll be reacted W1th an excess .of SOg.. Both the 502

and the Fz will be preheated electrically to 300 to 400 F and then fed

'1nto a Mbnel reactor wrepped'W1th steam coils. The steam'w1ll serve the
'”dual purpose of keeping the reactor warm.to 1n1t1ate the reaction and of
.,cooling the reactor after the reactlon is started. _The reaction is

 strongly exothermic and proceeds smoothly at 400° Fo VThefproduet_is SO02F5,

a‘relatlvely inert gas, which will pass through the caustic serubber,~the

 
 

18

activated-charcoal trap, the chemical plant=fi1ter,~and the main filters
and stack. ' ' |

2.2.6 Off-Gas Handling

 

The fluorination off-gas stream, after reaction of the fluorine with
- 80, will pass through a caustic scrubber, . The excess SOé and the SO0.F>
will be partially neutralized by the caustic. However, the main purpose
of scrubbing the fluorination off-gas is for the removal of fission prod-
ucts, since the SO2 and SO,F, can be safely passed through the: filter
system. The scrubber tank off-gas will pass4through an activated-charcoal
. trap for additional fission-product removal before entering the cell ven-
tilation duct just upstream of the absolute filter in the spare cell.

-The cell air will then go to the main filters and be discharged from the
100-ft containment stack. '

2.2.,7 Liquid Waste Disposal

 

The caustic scrubber will be charged with 1300 liters of 2 M KOH.
This will be sufficient caustic for the complete neutralization of 50
liters of S0 per minute for 8 hr with a final molarity of 0.33. Since
some of the S0, will be consumed by unreacted fluorine and the SO;F, is
expected to hydrolyze slowly, changing the caustic solution every 8 hr
should provide a considerable margin of safety against the solution be-
coming acidic. The 8-hr caustic cycle will begin at the start of SO,
flow (2 hr after the start of Fa flow). |

When processing has been stopped for replacement of the caustic (and
for salt sampling and replacement of the fluorine trailer), the batch will
first be sparged with helium for 1 hr to remove dissolved UFg and Fz and
-reduce corrosion during downtime. After sparging has been completed, the
caustic solution will be jetted to the liquid waste tank, and fresh

caustic will be charged to the scrubber. - | |

2.2.8  Waste Salt Handling

After removal of uranium from the fuel salt; it is planned to add
0.2 mole % of highly enriched uranium (salt B) to the salt and proceed

 

 

 
»

”n

»

#»

A}

19

with the second phase of;thg_rrogram,_.After the second phase is complete,
thorium and additional uranium will be added to the same salt to form
salt A. TUnless some unforeseen contamination of the fuel salt occurs that
renders it unsuitable for further uée;rthe same salt should be usable for
the entire program. o ”

At the end of the program the salt will be held molten in either the

‘fuel storage tank or one of the drain tanks until it is certain the salt

will not be required for further operations or samples. A heated, insu~
lated line is provided-frbm[the’fuel'storage'tank through the shielding on

‘the east wall to thé’spafeéégliifor eventual removal of the salt. The dis-
‘posal method has not been determined at this time. - This line can also be

used for salt removal if thié’is'reqnired[befbre the end of the program.

When not in use the line is sealed by a freeze valve in the fuel-process-

ing cell and. a blind flahge:in the spare cell.

 
 

 

 

20
3. EQUIPMENT DESCRIPTION
3.1 Plant Iayout

The main portion of the fuel-handling and -processing system is in
the fuel-processing cell, immediately north of the drain tank cell in
Building 7503, as shown in Figs. 3.1 and 3.2. The gas supply station is
outside the building, west of the drain tank cell. The off-gas filter,

. hydrogen flame arrester, activated-ghércoal,trfip, and fiaste;salt remova.l
line are in the spare cell east of the fuel-processing cell. The system
will be operated from the high-bay area over the cell, where a small in-
strument paneiboard is located. Also'in the high-bay area are the salt-
charging area,'the UF¢ absorber cubicle, the salt sampler for the fuel
storage tank, and an instrument cubicle. The instrument cubicle contains
the instrument transmitters and check and biock valves connected directly
to process equipment, and it is sealed and monitored. Figures 3.3 and
3.4 are photographs of the fuel-processing cell and the operating area,
respectively.

3.2 Maintenance

Since corrosion is expected to be very low during‘Ha-EF treatment and
only two or three fluorinations are planned, maintenance problems are not
expected to be severe. The system, with a few exceptions, has therefore
been designed for direct maintenance, with savings in cost and complexity

of equipment. The exceptions are the NaF trap and two air-operated valves.

The NaF trap may become plugged by volatllized chromium fluoride during

- fluorination and must be removed from the system before aqueous decontami-
nation. It is therefore flanged into the system and has disconnects for
thermocouples and electrical power. The valves have flanges with vertical
bolts and disconnects for the air lines. The valves and trap are located
under roof plugs sized to pass through the portable maintenance shield.
This shield can also be used for viewing and for external decontamination
of equipment should this be required because of & leak. All heaters in
the cell have duplicate spares installed.

@

 
H » N " ]

 

ORNL-DWG 63— 434TA

FUEL PUMP
. LUBE OtL SYSTEM

;f

   
 
   

 

   

COOLANT PUMP
LUBE OIL SYSTEM

    

   

| B%MRY OFFICE

 
   
 

MAINTENANCE

ShoP CHEMICAL

LABORATORY

   
   
  
 
 
    
 

 
 

A To FILTERS

TUBE -

  
 

 

~FUEL

 
 
  
 

 
 
  
  

 
    

' VENTILATION

 SPECIAL |

C- ‘
EQUIP DUCT AND BLOCK VALVE
TO VAPOR: '

  
   
 
 
  
  
    
 
  

        
      
 
 

.- COND, SYSTEM

   
 
  
   
  

- ROOM

 
  
  
 

      
 
 

o CUE e SPARE
MAINTENANCE €.
PRACTICE STORAGE CELL -COOLANT PUMP N
UCELL CELL - : H
COOLANT |

    
  
 
  
 

 
    
  
   
 
    

 

| INDUCTION
B REGULATOR
1 cELL ‘ SALT DRAIN
| LIQUID WASTE TANK
CELL ST
VENT
N

-HOUSE

 

 
  

 
 
 
   
  

 
 
  
   
  

DRAIN. .
TANK NO. 2

FUEL =

 
   
  
 

. DECONTAMINATION ‘
. CELL - SALT ‘
RADIATOR

'STORAGE SHIELD

  

FUEL SALY

       
    
 
 

 
 
 
   

   
   
 

. TANK
. ADDITION FLUSH
- STA FUEL
i PROCESSING DRAIN
CELL . TANK NO.1.
: REACTOR :
*ELEC. SERVICE AREA BELOW CELL ANNULUS BLOWERS
RADIATOR
BLOWERS

Fig.' 3.1. TFirst Floor Plan of MSRE Bullding.

 
 

ORNL~DWG 84-397A

11 2 3 49 5 6 7‘ 8 3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

 

 

  
   

 

   
  

 

 

 

 

  

L
J.——30-ton CRANE 3 AND 10-fon CRANES .
= Gié%%éfiifr
STACK
g COOLANT SALT
r?:_-:::::::::::.l-] PUMP
H MAII\CIJL‘::.'TNAC;NCE ! 5 gH:)ELDS )
: | ~ CONTROL ~ ! LOCK
. DECONTAMINATION EECETOR tL____Room 1t [ . o
| ) \ ed|
SHIELD BLOCKS STATION  BLOCKS, \” FUEL PUMP, ™ Al
. ‘ , I—‘ o | o | —| A
. ] 5 10 I e
‘ T AT ;:»- g 2 : - Al e
’ 4 \ r HEAT i .
el | I EXCHANGER D
| M orommrdf 2‘ ‘
= 1 LIQUID WASTE |1 : . i '
H = CELL e 4| | 3 T1 T
s s DRAIN TANK CELL E L_J\
FUEL o RADIATOR
STORAGE TANK T T _ i BYPASS DUCT
PROCESSING UL L R TR L
CELL ok U Ay
L2 N COOLANT SALT
e e < _ DRAIN TANK
FUEL DRAIN FUEL DRAIN REACTOR
TANK NO.1 FLUSH LINE = . VESSEL
% _ TANK ‘ | o
" FUEL DRAIN ‘ THERMAL

'TANK NO. 2 . U SHIELD

Fig. 3.2. Elevation Drawing of MSRE Building.

(Td . | ’ l N | | - . (:>

 

 

 
 

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Fig. 3.3.

MSRE Fuel-Processing Cell.

0

 

 

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25

_ If a piping or equipment leak occurs, or if entrance into the cell

is required for other’reasons after irradiated fuel has been processed,
aqueous decontaminetion will be required. The recommended method is de-
scribed in report ORNL-2550 (ref. 3) and consists of (1) barren salt
flushes to displace as much as possible of the irradiated salt, (2) aqueous
ammonium oxalate flushes to remove the salt film, (3) nitric acid-eluminum
nitrate flushes to remove metallic scale from the surfaces, and (4) sodium
hydroxide—hydrogen peroxidé%sodium tartrate flushes for gas line decon-
teamination. More details onfthese decontamination procedures are given

in Section 5.3. | '

 

353 In-Cell Eguipment

3.3.1 Fuel Storage Tank

The fuel storage tank-in vhich chemical processing will take place is
similar to the reactor drain tanks. The tank is shown in Fig. 3.5, and
design data are given in Table 3.1.

The height of the etorage tank was increased by 30 in. over the height
of the drain and flush tanks to minimize salt carryover due to sparging
during chemical processing.  About 38% freeboard is provided above the
normal liquid level. | | |

The tank is heated by'four sets of heaters in the bottom, the lower
half, the upper half and the top of the tank. -Each set of heaters is
controlled separately with variacs., Every heater has a duplicate installed |

':spare w1th leads outside the cell The heaters are mounted on a frame that
'is supported from the floor to minimize the tare weight on the weigh cells.

The fuel storage tank is prOV1ded with air cooling to permit recelving

1 fully irradiated fuel salt after four days decay (the minimmm.time deter-
 mined by xenon evolution) Since the fission afterheat load of a fuel
e'batch that has decayed four days after a full-power year of operation will

'_be greater than 25 kw (see Fig 3 6) and the maximum.expected heat loss

- from the fuel storage tank is’ approximately 18 kw, some method of cooling
.was required, If the minimum expected heat loss (5 kw) from the tank vere

realized, cooling would be required after one full-power year of operation

 
 

 

 

26

ORNL-DWG 65-2509

SAMPLER
LINE
4 SALT
INLET
GAS _  imier AND
OUTLET OUTLET
- LINE

SUPPORT

R|NG-..‘ ,o\

BAFFLE

L |

 

6in.
IPS —a
=—{-in. AIR

AIR .
OUTLET ;_

 

v

 

  

 

 

I hhhiae

-

 

-
&= -

COOLING . _ :
AR U"‘ STABILIZER

 

 

 

50 in.

Fig. 3.5. Fuel Storage Tank.

1
1
I
|
|
I
|
{
1
I
{
|
I
1
I
1
i
i
| . .
i g 16 in. -
}
I
1
1
|
|
i
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i
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1
|
t
1
1
{
|

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11

 

 
 

 

 

 

 

 

 

 

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27

 

ORNL-DWG 635-25{0
. — 1000 -

.

P

IRRADIATION PERIOD (days)
DECAY PERIOD (days)

«

n

 

O B 0 a8 20 0 cR8 0 (0 30 - T35
T TR BFTERHEAT W) o 0 T -

A

. Fig. 3.6. Fission Afterheat Based on MSRE Operation at 10 Mw. .

 

"

 
 

 

28

Table 3.1 Fuel Storage Tank Design Data

 

Construction material | INOR-8
Height, in. ‘ ~116
Diameter, in. = , 50
Wall thicknesé; in. .
Vessel ' | 1/2
Dished heads " - B 3/4
Volume at 1250°F,fft3 o |
Total 117.5
Fuel (min, normal fill conditions) 73.2°
Gas blanket (max, normal fill condltions) by, 3
Salt transfer heel, max 0.1
Design operating temperature, °F 1300
Design operating pressure, psig ' 50
Beater capacity, kw |
Bottom (flat ceramic) 58
Lower half (tubular) | 11.6
Upper half (tubular) 5.8
Top (tubular) 2.0
Insulation, in. 6
Reference drawings
Tank assembly D-FF-A-40430
Tank support E-NN-D-55432
Tank housing : E-NN-D-55433
Tank heaters - E-NN-E-56413
Tank heater details - E-NN-E-56414
Thermocouple locations D-HH-B-40527

 

unless over 100 days decay was allowed. Therefore, to avoid possible long -

decay times before being able to transfer a fully irradlated fuel batch -
to the fuel storage tank for hydrofluorination or in case it was necessary
to remove the batch from the drain tenk cell to permit maintenance opera-
tions, cooling of the fuel storage tank was desirable. N

" A simpler, less expensive method of cooling than the boiling-water
cooling in the drain tanks was desired. A preliminary study® indicated
that cooling by natural air convection was feasible with only 2 1/2 hr
decay. A maximum heat load of 72 kw was assumed with an air temperature

O

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n

a

29

rise from 150 to 660°f.  However, the cooling requirement in the fuel
storage tank will be much less than 72 kw for the following reasons:

1. A minimm decay time of four days will be used instead of 2 1/2
hr. " L T
2. The operating period will probably be less than one full-power
year. - |
3. Some gaseous fission products will be stripped in the punp bowl
and some will'plete'out’on'cedler surfaces in the reactor system.

4. A heat loss of 5 to 18 kv is expected through the tank insulation
and by radiation.

Instead of natural convection, a positive air flow is provided by
routing the cell exhaust ain through a 1l-in. annular space between the

fuel storage tank wall and'the tubular heaters on the inside of the in-

sulation support can. A thin stainless steel sheet is installed in this
annular space about 2 ft from the top of the tank to restrict air flow up
the tank wall when the dampers are closed. It will also be necessary to
seal all penetrations threugh the top cover as well as possible to prevent
unwanted air flow. A 1-ft2 opening with a gravity damper is provided at
the bottom of the tank. There is a similar opening through the side of

“the insulation support can at the normal liquid level.  This outlet line

has a motor-operated damper endeis ducted directly to the cell air ex-
haust. When cooling is not required, this damper is closed and another
motorized damper, which allows cell air to bypass the fuel storage tank,

rls opened With a BO-kwrléad?and*500ift3/min'Of'air flow (the nominal
, cell exhaust rate), an air temperature rise of approximately 200°F has
!rbeen calculated:. S R | '

The tank’ has tvo dip tubes, one for gas 5parging and ‘the other for

'?eeharging and discharging salt The sparge line 1s 8 1 in. pipe that is
;:closed at the bottom and has fbur 1/2-in. holes 90° apart near the ‘bottom.
'3réfThe salt dip tube lies on. the ‘bottom of the tank at the center to minimize
1:holdup (approximately 0. l% of a batch) Liquid level is determined by
_:zweighing the tank with two pneumatic weigh cells. The weigh cell calibra-
:tion can be checked by two single-point level probes. Other instruments

provided are 13 surface-mounted thermocouples and a pressure-recorder alarm.

 
 

 

30

C

An interlock is provided that prevents_salt'backup in the gas sparge
line in case the tank pressure exceeds the sparge-gas pressure. Another
~interlock prevents backup of tank off-gas (UFG; HF, ¥, or fission gases)
into the sample line, which is also connected to the pressurization—
pressure recorder line in the high-bay area. This is done by closing the
HF-F» valve if the tank pressure exceeds the hélium purge pressure. The
vent valve in the off-gas line opens if the tank pfesSurerexceeds the
designrpressure of 50 psi. The tank pressure will slarm above the normal

11}

pressure of 5 psi to indicate any plugging in the off-gas line, trap,

valves, absorbers, or caustic scrubber. - S _ s

3.3.2 NaF Trap

The NaF trap will be required mainly during fluorination to provide
additional decontamination of the UFg gas and to remove volatile chromium
fluorides from the gas stream. A kilogram or more of chromium fluoride
could be volatilized during fluorination, and it would collect in lines
and velves and eventually cause plugging. .The trap is shown in Fig. 3.7
and design data are given in Table 3.2. |

The gas enters on the outside of an internal cylindrical baffle and
leaves inside the baffle, and thus the gas path is almost 2 ft for a 12-in.
depth of pellets. Gas velocities are kept below 4 ft/min to prevent
carryover of fines containing absorbed fission—product‘fluorides.

The trap has thermowells at the inlet, center, and exit. Heat is
controlled by separate variacs for the center and the outside.of the bed. -
Spare heaters are installed.

Since there is a possibility of plugging of this trap with chromium -t
during fluorination, it is designed for remote replacement. The inlet
and exit lines are provided with ring-joint flanges at the'trap and some
distance away to permit removal of éections of the lines for access to
the frap. Thermocouple and electrical disconnects are provided on the
trap, and & standard lifting bale is mounted on a strap over the trap.
Before the firét fluorination of radicactive fuel, a spare unit will be
. fabricated.

"

 
 

 

 

 

"

-

»

31

ORNL-DWG 65-2511

 
   
     
     

 

LIFTING
o . 3 FRAME
LIFTING
BAIL

 

 

THERMOWELLS

OUTLET

 
 

 

   

 

 

 

i |
v o I i
! i l : i
| |: ‘ | '
Lo ]
i i | |
e | I
A
oo ' '
18in, | H | HEATING I
4 11 'eeeoren|] i
L AT TOP | '
\ ] oNLY i
= U |
I ! | '
"\BAFFLE | ! !
i !
i |
I |
2. .______'_'___ zom.-————'- o

 

paiin mho.

 
 

 

32

Table 3.2. NaF Trap Design Data

 

Construction material : Inconel
Height, in. ' ‘ 18 '
Diameter, in. - : . 20
Wall thickness, in.
Sides .- . 1/8
' Dished heads - 1/4
Loading, kg of NaF pellets = 70
Design operating temperature, °F. 750
Design opérating pressure, psig . 50
Heater capaéity, kw | | '
Center o ' | 2.25
Outer surface .9
Insulation, in. | | : 4
Approximate loaded weight, 1b 500
Reference drawings |
Tank details D-FF-C-55446

Feater details E-NN-E-56412

 

The trap will be removed fromrthe cell if aqueous decontamination is
necessary to permit direct maintensnce on cell components. In this case
the trap will be replaced with a jumper line to permit flow of solutions
through the entire system. Since the bed will be very radiocactive after
fluorination of irradiated fuel, it may not be feasible to decontaminate

and reuse the vessel after removal from the cell.

3.3.3 Cold Trap

7 The extent of oxidé femoval from the salt during Hp-HF treatment will
be determined by cold trapping the off-gas stream and measuring the volume
of water and HF condensed. The cold trap is shown in Fig. 3.8, and design
data are given in Table 3.3. The inlet end of the trap is in the northwest
corner of the cell and the trap extends eastward with a 3° slope. The in-
let and outlet brine connections are reducing tees at each end of the
Jacket.

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33

 

 

 

THERMOWELL\
1% -in. CORK 1-in. IPS STEEL JACKET
OUTLET INSULATION ,
J o 4-in. 1PS MONEL PIPE
. 1 : : \l\
R0 ——1 -
INLET b d

 

 

 

 

 

 

1 ; - V.I:of'msn.-—_______rr ' .i

¥,-in. 1PS MONEL PIPE

-BRINE INLEY
—.

%4-in.-OD COPPER TUBING

ORNL-OWG 63-2512

_V_A_FOR OUTLET

___—I——BAFFLES

2in,

 

    
 

 

| THERMOCOUPLE

—t
CONDENSATE
QUTLET

!14’“!.‘00
0.065-in.- WALL
MONEL TUBING

Fig. 3.8. Cold Trap and Siphon Pot.

 
 

 

 

34

Table 3.3. Cold Trap and Siphon Pot Design Data

 

Construction material Monel
Cold trap
Moximum vapor velocity, ft/min 1800
Meximum expected heat load, Btu/hr 2500
Heat transfer surface area, ft2 2.3
Siphon pot volume, cm3 55
Brine system
Brine Freon-11
Brine flow rate, gpm 5
Brine head, ft (max) 40
Brine volume, gal (min) 2.5
Reference drawing E-NN-D-55439

 

3.3.4 Siphon Pot

The condensate from the cold trap collects 1n a pot that automatically
siphons when full. The pot is shown in Fig. 3.8, and design data are given
in Teble 3.3. The exit gas passes over a thermowell for accurate deter-

mination of the off-gas temperature. The pot is cooled by the brine before

the brine enters the cold-trap Jjacket. The siphon tube has a surface ther-
mocouple cutside of the thermal insulation to detect each siphoning.

3.3.5 (Caustic Scrubber

 

The caustic scrubber is shown in Fig. 3.9, and design data are given
in Table 3.4. The tank is provided with colls enclosed in a heat-transfer
medium. During Ho-HF treatment, cooling water will be circulated through

the coils to remove the heat of HF neutralization. During fluorination,

it may be desirable to use steam to maintain the caustic solution at an
elevated temperature for better tellurium scrubbing. ‘

The tank is provided with a thermowell, a liquid-level bubbler tube,
and a Jet sfiction line. The used caustic is Jjetted to the liquid-waste
tank when the molarity has been reduced from 2.0 to appfoximatély 0.3 M
KOH. A caustic charging line is provided from the high-bay area.

 

 
 

 

 

»

35

ORNL-DWG 65-253

THERMOWELL

    
  
  
 

oo

CAUSTIC
CHARGING
LINE

JET

— }

 

~LIQUID
LEVEL

. BUBBLER .
TUBE

 

 

COOLING
WATER
QUTLET .

 

84in,

- HEAT -
TRANSFER

CEMENT. 48in.

COOLING €
WATER
INLET

 

 

 

 

 

 

18in,

-r'[fljig; 3;9;;:CduéficSCfuBbér{

 

4

 
 

 

36

Table 3.4. Caustic Scrubber Design Data

 

Construction material " Tnconel

Height, in. 84
Diameter, in. 42
Wall thickness, in.

Vessel 3/8

Dished heads ' 3/8
Volume, liters '

Total o : 1600

Normal fill . - 1300
Design operating temperature, °F 200
Design operating pressure, psig 50
Beat transfer ares, ft?2 45
Liquid head, psi “ 2.15
Reference drawing . - E-FPF-C-55441

 

- The off-gas from the scrubber tank is routed to the spare cell where
it passes through an activated-charcoal trap and a flame arrester before
discharge into the cell ventilation duct. The gas should be free of air
or oxygen up to this point, since all purges are made with helium. A
sensitive pressure indicator will show any restrictidn in the off-gas line

or flame arrester.

3.3.6 NaF Absorbers

The absorbers for collecting UFg on NaF pellets are made.of carbon
steel, which is sufficiently resistant to fluorine for the short exposures
involved. The absorbers will'be used for processing only one batch and
will then be discardedito the burial ground. The absorbers are shown in
Fig. 3.10, and design data are given in Table 3.5. A bed depth of 6 to
10 in. (14 to 24 kg of NaF) will be used. The actual depth will depend
on the amount of uranium to be absorbed. With fuel salt C, three sets of
absorbers will be required, while with salt B only one set will be needed.

FEach absorber is mounted in an open top container with an air dis-
tributor pipe in the bottom. Cooling air flows around the dutside and up

in

"

 
 

 

 

 

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37

ORNL~-DWG 65-2514

   
  

THERMOWELL

MA‘fE RIAL: _
CARBON STEEL

T OUTLET

 

PIPE OPEN AT

»AIR COOLING
(TOP AND BOTTOM

 

 

 

 

 

 

 

 

N 1 T
1o ] 3
W | |
__ i 0
Tin. ;'I _ | | |
' _.1{' ) | |
i | ' i
i ' | | 12in.
i b I
y P |
. | |
| | | i
SN b |
- \\BAFFLE :' :
— '14lin.'

| Fig. 3.10. NeF Absorbers.

 

 

 
 

 

38

Table 3.5. NaF Absorber Design Deta

 

- Construction material Carbon steel.
Height, in. 12
Diameter, in. 14
Wall thickness, in.
Sides 1/8
Dished heads 3/8
Design operating temperature, °F 750
Design operating pressure, psig | 50
Ioading, kg of NaF pellets | 1424
Bed depth, in. 6~10
Reference drawings
Absorber details D-FF-C-55447
Absorber container detalls D-FF-C-55448

 

through the open 2-in. center pipe. Air can be controlled separately to
each absorber.

Each absorber 1is provided with-a thermowell immersed in the NaF pel-
lets near the gas inlet. Since absorption of UFg to form UFg* 2NaF liber-
ates 23.9 kcal per mole, the start of UFg absorption and the breakthrough
to the succeeding absorber in the train can be followed by cbserving the
temperature rise.

The absorbers are connected with jumper lines having ring-joint
flanges with pigtails for local leak detection before sealing the cubicle.
The lines in the cubicle all have tubular heaters to prevent UFg conden-
sation. No spares are installed because thé cubicle is accessible to the
high-bay area when processing is stopped. |

3.3.7 Fluorine Disposal System

 

Tthexcess fluorine is disposed of by reacting it with S0, to form
S0,F5, which is a relatively inert gas and can be safely passed through
the Fiberglas filters in the off-gas system. Design of the system is
based on the system in use at the Goodyear Atomic Corporation at Ports-
mouth, OChio. Since the quantity of fluorine to be dispoéed of is similar,

ey

"

i

i

 
 

 

”

o

"

39

the same size eqfiipment is used, except for the fluorine preheater. The

fluorine at Portsmouth is diluted to about 10%, while the fluorination

off-gas will be nearly 100% fluorine toward the end of the processing.
The fluorine preheater can therefore be the same size as the S0, preheater,
Some construction details have been changed to adapt the equipment to re-
mote radiocactive service.

The equipment is shown in Fig. 3.11, and design data for the system
are given in Table 3.6. Both gas streams are preheated to 400°F before
contacting in the fluorine reactor. Each preheater has three separate

Table 3,6.7_Fluerine Disposal System Design Deta

 

Construction'material ,

SO, preheater: Type 304L stainless steel
F, preheater and reactor = =  Monel
Iength, in. S
Preheaters : ef.f-- - 30
Reactor , '
Overall : 112
Reaction zone - - 96
Diameter, in. IPS -
Preheaters S 2
Reactor o , 5

Design fluorine flow, 1iters/min 100
'-Design operating temperature,._E;_&_-

" Preheaters o e00
-Reactor o 'fff . - 750
Design operating pressure, psig 20

 Heat capacity of heaters on each 1.5
‘preheater, kw - o .

~ Insulation, in. ,_.1._;;__;;_ 2
:eReference drawings._e $;e;:_]: o S
80, preheater S . D-FF-C-55445
F, preheater - - D-FF-C-55444
‘Fpreactor -~ - D-FF-C-55442
Preheater heaters R E-NN-E-56410

 

 
 

 

 

S0,F>
OUTLET

S-in.
MONEL PIPE—~_

00in.  STEAM | L
OUTLET
—‘—=—-

8

44 in.

€]

 

 

J &

| —=

STEAM

 

 

-
SO

F, REACTOR

THERMOWELLS

THERMOWELLS

HOLES FOR Fp
F, INLET
o INLET

5

3Qin.

 

 

=71\

 

 

 

SO, AND F,
PREHEATERS

INLET \EiGHT 3g-in. DISTRIBUTOR

- 2-in. PIPE

17 HEAT

> TRANSFER
RODS

Fig. 3.11. Fluorine Disposal System.

ORNL-DWG 65-25{5 . _

18in,

 

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41

heaters with installed spares. Each heater is controlled separately by
an off-on switch The lOWhpreS gure steam coil on the inlet half of the
fluorine reactor supplies heat ‘at the start to 1nit1ate the reaction and

acts as a coolant to remove the heat of reaction after the reaction begins.

.It 1s_desired to keep the temperature below 1000°F to minimize corrosion.

3.3.8 Cubicle Exhauster

 

The air in.the absorber cubicle is maintained at a 2-in. H50 negative
pressure with respect to the high-bay area by'an exhauster located in the
fuel-processing cell. This is an exhauster with a capacity of 250 cfm at
10.5 in. Hp0. Tt is driven by a 3/4-hp 3450-rpm 440-v 3-phase motor. The

rsuction side is connected to the cubicle by a 4-in. steel pipe routed

through the space west of the cell The dlscharge 1is open to the cell
without any connecting piping A 4-in plug cock is prov1ded in the suc-
tion line in the cubicle, vith an access flange on the cubicle, to permit
closing the valve with the gasketed top in place for leak checking.

The blower is controlled by a manual switch with an interlock to a
solenoid valve in the cooling alr supply to the absorbers. This ensures

that the cooling air cannot be turned on 1nadvertently'w1th the blower

. off and thereby’pressurize the cubicle

 

_3.4_Out-of-Cell Equipment

_f3 4.1 Activated-Charcoal Trap

An activated-charcoal trap is located in the off-gas line in the

- spare cell, The main function of this trap is the removal of iodine from
'_fifthe off;gas stream._ The trap consists of two 4 3/8 in.-diam, 10 l/2-in -
“long canisters in series, each with & charcoal depth of 3/4 in, The
_canisters are installed in a-flanged 6-in Monel pipe 50 that they can be
'1irep1aced if necessary Each canister contains 1. 5 1b of 6- 14 mesh char- |
-?ecoal and is rated to prccess air at a max1mum,of 25 fts/min Each canister
:fphas an’ exposed.surface of l ft2 _ The pressure drop througb one .canister
at 25 ft3/min is 0.15 in. Hy0. |

 
 

 

 

42

O

3.4.2 Flame Arrester

Since the system will be completely purged of air before processing
' begins and all purge and sparge gases will be helium or nitrogen, there
is no possibillty of producing an explosive mixture‘with hydrogen in the
equipment. The only location involving an explosion hazard should be the
point of discharge of the off-gas into the off-gas duct. At this point
the maximum concentration of hydrogen in the air is O, 65%‘with a hydrogen
flow rate of 90 liters/min and a cell air exhaust of 500 cfm. This is :
well below the lower explosive limit of hydrogen in air of 4%. The cell
exhaust flow rate will be checked at the time of processing to confirm
that there is sufficient detection.

As an added precaution, s flame arrester is installed in the off-gas
line between the activated-charcoal trap and the cell exhaust duct in the

spare cell with a union downstream for removal for cleaning orlreplacement

e

The unit is a Varac model 51A and consists of copper gauze and disk lami-

nations.

3.4.3 0Off-Gas Filters

 

The fuel-processing cell ventilation air and the vessel off;gas will
pass through a 2-in.-deep 24- by 24-in. Fiberglas'prefilter and a 11 1/2-
in. -deep 24- by 24-In. Fiberglas absolute filter before pass1ng through
the main filters and containment stack. There are three 12-in.-diam but-
terfly valves for isolation and for bypassing of the filters for replace-
ment. A locally mounted differential-pressure transmitter indicates the

pressure drop across the filters on the fuel-processing System.panel board.

-

 The caustic scrubber off-gas, after passing through the charcoal trap and
the flame arrester, discharges into the duet Just upstream of the bypass
tee. ) ,

This equipment is located in the spare cell with sufficient space al-
‘lowed for the addition of 2 £t of shielding (for a total of 3 1/2 £t) be-
tween the filters and the fuel-processing cell. This should be sufficient
shielding to permlt filter changing with an irradiated fuel batch in the
storage tank

O

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43

3. 4 4 HF Trap

The fluorine used will contain up to 5% HF, which could cause plugging
of the WF¢ (by formation of NaF- 2HF, NaF:3HF, etc.) if not removed. There-

" fore the trap shown in Fig. 3.12 and described in Table 3.7 is provided

in the fluorine line at the gas supply station.

Table 3.7. HF Trap Design Data

 

Construction material : Nickel-plated carbon steel
Height, in. . 32
Dismeter, in. IPS - . 8
Design operating temperature, °F 250
Design operatlng pressure, psig 75
Operating:temperatures,'°F |

Inlet . o _ 272

Outlet ' 100
NaF-capacity; £t3 | - 1.9
‘Design flow rate, liters/mln 1 100
Reference drawing o - D-FF-C-55443

 

The inlet of the trap is maintained at 212°F by steam to prevent
plugging (by prevention of theeformation of the higher hydrogen fluoride

'-compiexes)'because of the high-partial pressure of HF. Farther into the
’NaF‘bed, the: HF partial pressure is lower and the higher- complexes are

‘not formed: even at. the Iower: temperature. The. exit of the trap is water

cooled to. about 100°F, which is below the operating temperature of the UFg

1'absorbers, and.the trap should therefore remove: any HF that could otherwvise

collect in the absorbers.u The reaction is exothermlc and liberates 16 4

-~ kcal per mole of HF. absorbed

With a. fluorine flow of 100 liters/min, a processing time of 10 hr,

and an HF content of 5%, the trap has sufficient capacity for the fluori-
frnation of five batches if only 50% of the NaF is complexed to NaF-« HF..

Since the average HF content is. less than 5%, one loading should have

 
 

 

 

 

ORNL-DWG 65-2516

FLUORINE ~~ - - FLUORINE -~

 

 

 

 

 

 

 

IN ouT
C rL 3 C l ]
, { ] [ ] 4
STEAM IN (J_/‘:[] WATER OUT
/ . -
= - ) - - - N N :
(_,_,4
) .
<% 32in.
STEam OUT [J— —{] WATER IN
- - S 8-in. IPS PIPE

 

 

 

 

 

 

 

 

 

| mem— | Smem—}

Fig. 3.12. HF Trap Filled with NaF Pellets.

 
 

 

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45

sufficient capacity for all the fluorinations planned at the MSRE. If

necessary, the NaF can be discarded and recharged.

3.4.5 HF Heater

The HF heater is installed in the gas line from the HF cylinder after
the flow control valve. 'The'purpose of this heater is to dissociate the
HF gas to the monomolecular form for accurate flow metering. This requires
the addition of approximately 1.2 Btu/liter of gas or approximately 20
Btu/min at the maximum.HF”flow rate anticipated (17 liters/min). Another

1 Btu/min of sensible heat is. required to heat the gas from 120°F, the

temperature of the gas at 25 psig leaving the cylinder, to 180°F, the
temperature required to reach,the monomolecular form. This 21 Btu/mln is
equivalent to 370 w. Two tubular heaters are used to'provide a total of
1120 w. - = , - |

The heater is strapped to the outside of a 2-in. Monel pipe about
22 in. long pecked with nickel wool for'heat transfer. The wool is con-
fined at the ends by 6 mesh Mbnel cloth. A thermowell is provided near
the outlet. '

3.4.6 Salt Sampler

The sait sampler in the fuel-prOCessing system is mounted on the

~roof plugs over the fuel-processing cell and is connected directly to the

top of the fuel storage tank by a vertlcal 1 l/2-1n pipe. The sampler
is the original erl-pump sampler-enricher mockup shown in Fig. 3.13. It

- is the same as the fuel pump sampler, with.the follow1ng exceptions'

: 1-, It is designed for a maximum of 14 peig instead of 50 psig. Area

'10 1s protected from overpressure by a pressure rellef valve that vents

to area 2B which 1s vented to the cell through the space around the 11/2-

' 7-in ‘sampling line,

2. No maintenance valve is requlred, since the system can be shut

*’down and purged if maintenance on the sampler is required.

_ 3.- Area 2B will contain the vacuum.pumps in addltion to the opera-

‘tional valve.

4. A bellows is installed between the operational valve and the

sample line instead of between the valves and area 1C.

 
 

 

 

 

46

s

ORNL-DWG 63-3848R

  
 
  

VALVE AND
SHAFT SEAL 2

LIGHT

  
  
 
 
   
 
  
 
 
 
  
  
 
  
  
 
 
 
 

CAPSULE DRIVE UNIT

JOINT (SHIELDED
ACCESS PORT WITH DEPLETED URANIUM)

AREA IC
(PRIMARY CONTAINMENT}

SAMPLE CAPSULE ‘MAN|PULfiTOR
3A (SECONDARY
CONTAINMENT }
SAMPLE TRANSPORT
CONTAINER

OPERATIONAL AND
LEAD SHIELDING

MAINTENANCE VALVES

AREA 28 { SECONDARY

SPRING CLAMP
CONTAINMENT)

DISCONNECT

TRANSFER TUBE
(PRIMARY CONTAIN

LATCH STOP

CRITICAL CLOSURES
REQUIRING A BUFFERED
SEAL S

   

MIST SHIELD m___g.
GLIDE FEET _

i%

Fig. 3.13. MSRE Sampler-Enricher.

w

 

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47

The sampler willnnotbensed during processing. The fuel storage
tank will be purged with helium before the operational valve is opened
for sampling. The main purpose of the sampler 1s to verify that the salt
is satisfactory for return to the drain tank after processing;: After
Hpo-HF treatment the sample will be analyzed to determine that HF and FeFy
have been reduced to satisfactory levels. After flnorination”the sample
will verify the complete remotal of uranium. Also, sampling.of flush salt
before processing will indicate the amount of fuel salt pickup.

The sampler will have,_in general,_the same instrumentation as the

fuel-pump sampler and will be operated in the same manner. °

3.5 Electrical System

 

Electrical power for the fuel-processing system is supplied by a
750-kva. 480/240-v transformer feeding a load center on the east side of
the remote maintenance practice cell on the 840-ft level. This 208-v
supply feeds two power panels, CP-A and CP-B, and starters for the two
motorized dampers for'the_fuelhstorage tank cooling air. The starter and
switch for the cubiclerblower are located at the load center but have a
separate supply since therhlower requires 440 v. Most of the equipment
and pipe heaters are controlled by switches or powerstats located at two
heater control panels, HCP-12 and HCP-lB, at the south end of the heater
control area on the 840-ft level east of the cell block. The pipe heaters
in the absorber cubicle are controlled by & switchiat'the cubicle in the

~high-bay area. The.line_and!eqnipmenthheaters are listed in Tebles 3.8

end 3. 9. LT e _ , |
The pipe 1ine and equipment heater, blower motor, and motorized

'7damper 1eads are routed from the heater control panels through 8 junction
;'box on the west side of. the decontamination cell-on: ‘the 840-ft level. At
this Junction box the spare heaters can be connected to the control panels

_1f necessary._ Each control may - have from one to n1ne separate heaters,

vhich are connected as a group at the junction box Defective heaters

':can be replaced only by entering the cell After the cell becomes radio-

active, only an entire group can ‘be replaced unless the cell is decon-

taminated to permit direct maintenance

 
 

Teble 3.8. Line Heaters

 

 

H-994-1, -2

Heat Heated Heat Maximum Maximum
Heater Location per Length per Voltage Current
No. Control Foot Setting Setting
(ft) . ‘
(w) (w) (v) (amp)
H-110-5 Cell wall penetration 1020 5.1 200 120 8.5
H-110-6 Cell wall to line 111 4584 25 187 140 32.8
H-110-7 Freeze valve 111 to fuel storage tank 1496 8 187 - 140 10.7
H-110-4 End of penetration | 270 | 90 3
B-111-1 Freeze valve 111 to cell wall 3743 - 20 187 140 26.7
 H-111-2 Cell wall to high bay 2620 14 187 140 18.7 &
B-112-1 Line 110 to spare cell 2432 13 187 140 17.4
- H-690-1, -2 Fuel storage tank to valve HCV 694
" 2620 14 187 140 18.7
H-694-2 Fuel storage tank to cell wall
H-691-1, -2 Fuel storage tank to NaF trap | |
H-692-1 to 4 NaF trap to absorber cubicle 1245 60 21 © 120 10.4
H-692-V ~ Valve HCV 692
H-692-5 to 12  Absorber cubicle 390 2 19 - 120 3.3
H~694-1 Valve HCV 694 to line 994 | " B ‘ |
| ; B ‘ 3202 16 20 120 2.7
Fuel storage tank to roof plug

 

®switch controlled; all others controlled by Powerstat.

 

 

 
 

 

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49

_ Table 3.9. 'Equipment Hbatersg_,

 

 

- Pots

_ Powerstat

2

o  Meximm
Equi 'ent. ~ Type of g Voltage Rgiiz
quipment ~ Comtrol Setting g
. oo Elements (w)
o (v) )
Fuel storage tank 7 |
. Top Powerstat 4 120 2,000
Upper side Powerstat 6 236 - 5,800
Lower side Powerstat = 12 236 11,600
Bottom Powerstat 8 226 - 5,800
NaF trap T
Side  Powerstat 2 240 9,000
Center - Powerstat 1 - 120 2,250
S0, preheater RS
No. 1 Switch 1 120 500
No. 2 - Switch 1 120 500
No. 3 switch 1 120 500
Fo preheater I | - |
~ No. 1 Switch 1 120 500
No. 2 . Switch 1 120 500
~ No. 3 , _ 'SM?:I_.F_(!I_I___E 1 120 - 500
HF inflihe heater  Switch 2 208 1,120
Freeze valve 110 - I |
‘Valve - Powerstat 4 115 . 1,200
Pots . Powerstat 4 110 - 2,210
 Freeze valve 111 | B
 Valve ' Poverstat = 4 115 1,200
. Pots .. Powerstat - 2 115 1,200
. Freeze valve 112 e | SR T
. Yalve = -Powerstat 4 115 1,200

115 1,200

 

8 he&tersfare*tfibfilar'éxc6pt those on freeze valves and

~__ fuel storage tank bottom, which are ceramic. Duplicate spares ..
- are installed on all equipment except the HF heater. Heater

controls are on panels HCP-12 and HCP-13 on the 840-ft level.

 
 

 

 

50

3.6 Helium Supply System

 

The helium supply to the fuel-processing system is fram?the 40-psig
helium header in the water room. At the fuel-processing panelboard in the
high-bay area, this supply is reduced ét a 20-psig transfer header and a
13.5-psig purge and sparge header. The transfer header has an air-operated
block valve that cannot be opened unless freeze valve and drain tank vent
valve positions are correct to receive a salt batch from the,ftél storage’
tank. The purpose of this interlock is to prevent accidéfital filling of
the reactor or tfansfer to a tank already containing a salt batch.

The purge and sparge header has sufficient pressure (13.5 psig) to
permit éparging a salt batch at 100 1itefs/min but has insufficient pres-
sure to force salt over the loop in line 110 (14.6 psig, min). This
header is provided with a pressure-relief valve set at 14.0 psig, which
will reseal at 12.6 psig. ©Should this valve stick open or the helium
supply pressure be lost for any other reason, an interlock on the helivm
purge flow to the system will close the Ho-HF-F, supply block valve, stop
the evolution of fission-product gases, and prevent the possible pres-
surizing of corrosive or radiocactive gases up the sample liné fb the high-
bay area.

Other functions of the low-pressure header are to supply gas for
instrument- and sample-line purging, for purging the salt charging line
above the freeze valve prior to salt transfer, and for purging the HF and
F2 lines from the gas supply station to the fuel storage tank.

3.7 TInstrumentation

 

3.7.1 Thermocouples

All the temperature-measuring points in the fuel-processing system
are listed in Table 3.10. Two 12-point recorders (0-250°F and 0-1000°F)
are installed on the fuel-processing system.pénélboard thafirwiil record
all measurements normally required for Hp-HF treatment. For fluorination,
additional low-temperature measurements are required, and the high-
temperature recorder and another low-temperature recorder temporarily
" installed for this operation will be used.

-

 
 

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51

 

 

 

 

Table 3.10. Temperature-Measuring Points
Number of Measurements Normally Recorded
Location N‘”;‘?er ,Igi:erzifirge Hp-HF Treatment ~~  Fluorination
0 .
Polnts  (°F) 0250°F O0-1000°F 0-250°F  O-1000°F
Recorder Recorder Recorder Recorder
NaF trap 3 750 3 3
S0, preheater 3 400 3
F» preheater 3. 400 3.
F, reactor 3 400 3
Line 691 2 200 2 1 2
Line 692 14 200 1 7 11
Valve HCV 692 1 200 1 1
Line 694 2 200 2 2
Line 994 2 200 2 2
Line 695 3 200 1
Line 696 1 180 1
NaF absorbers 5 100 5
Caustic scrubber 1l 100 1 1
Siphon pot 1 20 1
Line 695 B 1 20 1
Total 41 12 12 242 12
Line 690 3 '80=1000 _
Line 694 1 80-1000 Measurements will be made only in cases
Line 992 1 ' o " of emergency or for special tests
Line 993 1 Q c ' -
Fuel storage tank i3 '900-1200
Line 110 - 8 - 900-1200 : ' '
Line 111 7 - 900-1200 Measurements will be taken primerily
Line 112 3 900-1200 for salt transfer and will be re-
Freeze valve 110 5 80~-1000 corded in the main control room
Freeze valve 111 5 80-1000
5 80%1000

Freeze valve 112

 

An additional 0—250°F recorder will be temporarily installed :E'or fluorination

7 The readings of the 46 thermocouples installed on the fuel storage
tank, salt lines, and freeze valves will be recorded only'in the main

- processing, but changes should be slow.'

' control room, since- they will be required primarily for salt transfer.
”;The fuel storage tank temperatures will be checked occa31onally durlng

The four thermocouples on lines 690 and 694 Wlll be used only in

d"case salt backs up in line 690 and the application of heat is requlred
" to thaw a plug. The thermocouPles on lines 992 and 993 indicate the brine

 
 

 

 

 

52

inlet and outlet temperatures and will be connected for heat balance
tests or in case of operating difficulties.

3.7.2 Annunciators

The fuel-processing system.annunciator points are listed in Table
3.11. There are 11 ennunciators on the chemicsl plant panelboard. In
addition there are 3 radiation alarms that indicate high gamma activity
in the charcoal absorbers, 8 high gamma activity in the instrument cubi-
- cle, and a high gamma activity in the cell exhaust air. A portable alpha
air monitor will alarm on high air activity in the absorber cubicle and
there will be a high gamma level alarm on the fuel storage tank sampler
line.

Table 3.11. Arnuncistors

 

 

 

 

" Alarm
In;trau.ment ~ Service :

o Type Setting
PATA-AC Absorber cubicle to high bay Low differential pressure 1 in. E,0
PIA-CS Caustic scrubber vent High pressure 1 psig
PATA-FPC Fuel-processing cell to high bay Low differential pressure - O
PIA-530 Helium supply Low pressure 17 psig
PIA-604 Belium purge header - ~ Low pressure . 12 psig
PRA-608 Fuel storage tank vent ~ High pressure 30 psig
PICA-690 Fluorine supply ' Low pressure 25 psig
PATA-694 Purge to HF-F; supply Low differential pressure 1 psig
PIA-696 ~ HF supply High pressure 25 peig
FIA-608 Helium purge Low flow _ 3 1iters/min
TA-HFH HF heater ' , Low temperature - 200°F

. RTA-994 Sample line gamma activity "~ High activity '
RIA-IC Instrument cubicle gamma activity High activity
RIA-940 Cell exhaust air gamma activity High ectivity
RIA-AC- Absorber cubicle air monitor High activity
AF2IA-940A Cell ventilation fluoride content  High content ' "1 ppm
AF,IA-940B Vessel off-gas fluoride content High content 1 ppm -
AF,IA-628 Filter outlet gas fluoride content - High content , "~ 1 ppm

 

SThe 14 instruments above the line across the ta.'ble have panel-mounted annunciators,
the other 4 have slarms on the instrument.

4

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The panel-mounted annunciators will serve the following purposes:

Annnnciator_
Designation

PATA-AC

PIA-CS

PATA-FPC

PIA 530
PIA 604
PRA 608

PICA 690

PATA 694

PIA 696

. FIA 608

 mamm

Purpose

 

Indicate lack of negatlve pressure in the absorber

cnbicle, possibly due to blower failure or excessive
absorber cooling air :

- Indicate positive pressure in the serubber vent, pos-

s8ibly due to'plugging of the flame arrester or

activated-charcoal traps
" Indicate lack of negative pressure in the fuel-processing

cell, possibly due to fan failure, filter plugging, or
excessive air inleakage

Indicate a failure in the helium.eupply system or PCV 530
Indicate a failure in the helium supply system or PCV 604

Indicate high pressure in the fuel storage tank vapor
space; this could be caused by plugging in the off-gas
line, NaF trap, valve HCV 692, absorber train, or
scrubber inlet

Indicate the gas pressure in the fluorine trailer; with
a full trailer pressure of 55 psig, an alarm at 20 psig
will indicate the consumption of about 12,000 standard
liters of fluorine and that replacement of the trailer
is required

Indicate that the Hp-HF-F, gas pressure has been reduced
to within 1 psig of the pressure in the fuel storage
tank vapor space and there is danger of a back up of
salt into-gas supply line 690

Tndicate that the HF gas pressure in the cylinder is
reaching e dangerous level; this could be caused by
failure of the temperature control valve reégulating
the steam to the hot-water drum saround the cylinder

Indicate & lack of purge flow to the fuel storage tank
. and the possibility of backup of gaseous activity to

the instrument cubicle, this could be caused by lack
of helium.pressure or flowmeter plugging or incorrect

. setting

Tndicate insufficient heating of the HF gas, which -
could result in 1ncorrect flow meterlng

 
 

 

54

3.8 Brine System-

The siphon pot and cold trap are cooled by circulating fréon:bfiné
(trichloromonofluorcmethane).  The maximum cooling loads are approximately
2500 Btu/hr in the cold trap and an approXimately 1200-Btu/hr heat loss
from the piping and equipmeht.A Al 1/2-hp water-cooled refrigeration
unit should provide sufficient capacity for brine tempefatures as low as
~20°F. Brine is circulated by a cahned-motor pump'tfirough insulated
3/4-in.-0D copper tubing. The refrigeration unit.and:circulating pump
are located on the 840-ft level west of the cell. B

¥y

 
 

")

n

'tlon for diffusion from a contlnuous point source

55

4. BSAFETY ANALYSIS
4.1 Summary and Conclusions

A decay period of at-leaSt four days'should be allowed before trans-
fer of a fully irradiated fuel batch to the fuel stbrage tank to keep the
xenon level at maximum grdund concentration below 2.5 mr/hr. Under normal
atmospheric conditions, thlS concentration would occur 325 meters from the
stack. It would decrease rapldly with distance and decay time, as indi-
cated in Table 4.1 and Fig. 4.1.

Since no irradiated sait has ever been treated with Hz-HF, the fis-
sion-product volatlllzatlon ‘to ‘be expected is not known, but it should
be very low because of" the redu01ng condition of the salt. Volatilization
of iodine and tellurium is the most likely, but reduction and plateout in
the gas phase and final adsorption by the activated-charcoal bed should
remove most of the volatiliZed:aetivity. Much greater fission-product
volatilization is expected durlng fluorlnatlon, and longer decay times
will therefore be allowed befbre fluorinating flush or fuel salt.

The overall decontamlnatlon factors required to limit the release
of iodine to 50% of ‘the ORNL weekly 1imit® of 1 curie are listed in Table
4.2, along with the decontamlnatlon factors for the other volatile ac~

. tivities as determined by the maximum permissible concentration in air.

The only fission product of concern in processing with a short decay
time would be jiodine..

- Accidental. releases were also considered, and it was found that they

: would not result in exce351ve €xposures, since the process1ng operatlon

'-'could ‘be shut down rapidly upon 1ndlcat10n of exces31ve act1v1ty in the

off-gas stream.

~ 4;2}?Basesffor'Calculatiens -

"74.2.1 Diffusion.Facter,

| Gaseous act1V1ty concentratlons were calculated. us1ng Sutton s equa-‘
.7

 
 

 

56

ORNL-DWG 65-2517

PEAK XENON ACTIVITY (mr/hr)

 

0.2

3 4 5
DECAY ?ERIOD BEFORE PROCESSING {days)

Fig. 4.1. Radiation Level at Maximum Ground Concentration from Xenon
Released During Processing of Fuel.

#a

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57

 

 

 

 

 

 

Teble 4.1. Diffusion Factor, X, Versus Distance Downwind
‘X, Diffusion Factor™
Distance _
Down¥ind Inversion Conditions Normal Conditions
(m _
Ground Release Stack Release Ground Release Stack Release
100 2.1 x 1072 - <10710 8.0 x 1074 2.9 x 1077
160 9.8 x 1073 <1010 3.5 x 1074 1.1 x 10~°
200 6.3 x 1073 <1010 2.3 x 1074 2.3 x 107°
325 3.0 x 1073 <10-10 1.0 x 107% 3.7 x 107°
500 1.5 x 1073 2,1 x10°7 4,7 x 1072 3.0 x 1077
750 7.7 X 10~ 8.2 X 107 2.3 x 107? 1.8 X 1072
1,000 4.8 X 10°% 3.5 x 1072 1.4 % 10°2 1.2 X 1077
1,200 3.5 x 1074 4.5 x 107° 1.0 X 107° 9.1 x 107
2,000 1.5 x 1074 6.2 X 10?2 4.0 x 1076 3.8 x 1076
3,000 7.7 X 107> 4.9 X 10772 2.0 x 1076 2.0 X 1076
4,000 4.8 x 1072 3.6 X 1072 1.2 x 1076 1.2 x 1076
5,000 3.3 x10°°  2.7x10°° . 8.0 x 1077 8.0 x 1077
10, 000 1.1 x 1077 1.0 x 107° 2.3 x 1077 2.3 x 1077
%% x release rate (curies/sec) = concentration of activity in air
(uc/cc).
Teble 4.2. Decontamination Factors Required to Keep
Volatile Fission-Product Activity Below Allowable
Maximum Ground Concentration®
- Decay ~~ Decontamination Factor .
Period _— '

 

products, 10% of 40-hr MPC in air; Xp.y

:,(days)"UIOdihé]*:iTéiifirifim';Nidbium.'Ruthehiumfi,Ahtimony';

 

4 7.0x10° 57 48 31 <«
10 3.1x10° 26 - 47 29 <
20 1.0 X 10° .14 T A6 20 <1
30 4.0%x10% 11 - A5 18- <1
90 228 T4 31 9 <

 

®Fuel salt irradiated for one full-power year. Tol-
erances: iodine, 0.5 curie total release; other fission
’ s W = 3.7 X 1077 pefee
for a release of 1 curie/sec at 325 meters from stack. B

 
 

 

58

O

2 —
Q ,e_hz /c2x2-n
Te?ix? ~B
where

X = diffusion factor,

= release rate, curies/sec,

distance downwind of stack, meters,
= effective stack height, meters,

= diffusion constant,

wind velocity, meters/sec,_

0B X O
N

B 2]
il

it

stability parameter.

The following EGCR site diffusion parameters were used as recommended by
the U.S. Weather Bureau:® ' '

 

Inversion : Normal
Parameter Conditions Conditions
c? 0.01 0.09
u 1.5 2.3
n 0.35 0.23

As indicated in Table 4.1, the diffusion factor for a stack release under
normal conditions is at a meximum at a distance of 325 meters from the
stack, and the ground concentration is a factor of 20 less at the nearest
point outside the restricted area, as shown in Fig. 4.2.

The MSRE stack is 100 ft high and has & flow capability of 20,000
f£t3/min. An effective stack height of 163 ft, or 50 meters; was calcu-
lated:® | | |

 

4.77 QVS
hm= 7 X = 63 ft ,
v 1 + 0.43 = u
- Vg
where
hV'max = plume height above stack, ft,

=
n

mean wind speed, 7.3 ft/sec, o —

[y}

§r

3

 
 

2k

59

ORNL-LR-DWG 4406 R2

 

»

TO ORGDP
~5 mile

1®

“ 7 mzed '\ " 'f “SHIELDING
I FACILITY

»

 

   
     
  

" 'STRICTED AREA -

0N
20

o

“NEAREST POINT
OUTSIDE RE- .

 

 

. Fig. 4.2. ORNL Avea Map.

"

 
 

 

 

60

stack velocity, 47 ft/sec,
stack flow, 333 ft3/sec.

- VS
Q
Thus the effective height is 100 ft + 63 ft = 163 £t = 50 m.

4.2.2 Air Contamination

Exposures from gaseous activity are to be limited to 10% of the MPC
for a 40-hr week. All activity emissions will be averaged for a quarter,
although processing will require less than two weeks, because irradiated

fuel will be processed less frequentlyrthan once per quarter.

4.2.3 Activity in Salt

- The amounts of volatlle activity to be expected in a fuel salt batch
irradiated for one full-power year are listed in Table 4. 3 for various
decay times. When processing flush salt contalnlng 1rrad1ated fuel salt
the required decontamination factor will be smaller by the ratio of flush
to fuel salt, as determined from a salt sample. i

4.3 Gaseous Activity

 

4.3.1 Activity Release from the Containment Stack

4.3.1.1 Activity Released When Not Processing. A fully irradiated
fuel batch will be held in the fuel drain tank, with the off-gas passed
to a charcoal bed, until the xenon emission cannot cause a radiation

level in excess of 2.5 mr/hr at the point of maximum ground concentration.

. -From Fig. 4.1 it can be seen that an approximately fbur-dayedecay'period

is required before transfer to the fuel storage tank, which is not vented
through a charcoal bed. Since there is about 50 £t of gas space in the
processing equipment and the purge rate'will be lOW'when not processing,‘
there probably will be no xenon emission from the stack until prdceséing
actually begins. Because of the very'short half life of 8SB:r','.*;sK:r' emis-

| sion will be below the MPC 30 min after reactor shutdown.

4.3.1.2 Activity Released During Hp-HF Treatment. Although there
has been no work done on fission-product behavior under the highly re-
ducing conditions of the'HQ-HF treatment, very little if any fission-
product volatilization is expected. All the fission products that cofiid

O

n

W

 

 
*

 

 

 

 

 

 

» n » v n
. Teble 4.3. Volatile Activity in Fuel Salt Irradiated for One Full-Power Year
o | L . Volatile Activity (curies) -
Decay e e — '
Period ' 'Todine':: . ~Tellurium | S - |
(days) —m——————— ~ SN _ 95 103p,  125/127g
S 11 132, 127m 127 129m 129 132 - o
4 1.8%10° 1.7 x10° 4.5 x10° 1.3'x 10% 2.7 x 10* 2.7 x 10 1.6 x 10° 5.1 x 10° 2.2 x 10° 1.1 x 10% |
10 1.1 X 10° . 4.5 X' 10% 4.5 X 10° 4.6 x 10° 2.3 x 10% 2.4 x 10* 4.4 x 10* 5.0 x 10° 2.1 x 10° 3.8 x 103
20 4.6 X 10* 5.3 x10° 4.3 x10° 3.8 x 10° 1.9 X 10* 1.9 x 10* 4,9 X 10° 4.9 x 10° 1.8 x 10° 960
30 1.9%x10* 600 3.8 x10% 3.4 x10% 1.5x10% 1.6 x 10* 570 4,8 X 10° 1.5 x 10° 490
90 = 114 S 2,4%10% 2.2x10° 4.2 x10° 4.6 x 103 3.3 x 10° 5.5 x 10% 384

 

 

 
 

 

62

form volatile fluorides are more ndble than the,structurallmetals chromium,
iron, and nickel. Nickel, which is the most noble of the structural metals
will be limited to less than 1 ppm as NiF, with a 10:1 Hp-to-HF ratio.
Therefore, although no equilibrium quotients aie available for the fission-
product fluorides, it is unlikely that any niobium, ruthenium, antimony,
tellurium, or iodine will exist in the salt as the fluoride. However, it
is possible that'HéTe eand HI coui& fbrm.and‘become volatile. The activated
charcoal trap should provide good'décontamination from these activities.
The first treatment of salt contalnlng fission products will be a
treatment of flush salt contalning some 1rrad1ated fuel salt. This treat-
ment should provide the information needed for deciding on the required .
decay time for safe processing of a fully irradiated fuel batch. The ac-
tivity release will be follbwed both by gas sampling and by radiation |
monitoring of the off-gas stream. | -
4.3.1.3 Activity Released During Fluorination. Since considerable

 

volatilization of fission products is to be expected under the oxidizing
conditions of fluorination, the maximum possible décay time should be
allowed before processing. Based on Chemical Technology Division fluori-
nation experience, decontamination factors of 1 for jodine (cbmplete vola-
tilization), 1 to 10 for tellurium, and 10 to 10° for nicbium, ruthenium,
and antimony can be expected. From Table 4.2 it can be seen that the only
fission product that requires much additional decontamination isriodine,
end this should be obtained in the activated-charcoal trap. Additional
decontamination from most fission products will be obtained by plateout in
both the reactor and the fuel-processing system.by the 750°F NaF trap, by
the caustic scrubber, and by the filters.

Total release of the 114 curies of iodine present in the fuel after
90 days of decay, while considerably in excess of the 1 curie/week maximum
release as determined by the grass-QOWhmilkrhuman'chain, would result in
an exposure of only 0.3 rem in 8 hr at the'point of meximum ground con-
centration. This is only 3% of thejpermissible exposure due to accidental
or unusual releases. | |

4.3.1.4 Activity Released by Equipment Failure. Two possible ac-

 

cidents were considered. The first is the simltaneous rupture of the

"

"

"t

 

 
 

 

»

 

»

»

63

- fuel storage tank"and'the”caustic scrubber, which would result in vapori-

zation of the caustlc solutlon and thereby pressurization of the cell.
The second is a- gas-space. rupture during fluorination.
The simultaneous rupture of both the fuel storage tank and the caustic

scrubber and contact of the. two volumes could cause a rapid buildup of the

‘cell pressure to approximately 100 psig by vaporizing the 1600 liters of

caustic solution and releasing the associated activity to the building and

“up the stack. Contact is pfevented by an 18-in.-high dam that divides the

cell. The dam is sealed to the floor and to the north and south walls.

The sump is on the aqueous side of the dam, and water lines routed over
the salt side are provided with containment lines that drain to the agueous
side. , ' ' ' _

If there should be a rupture in the gas space of the fuel storage
tank or in the off-gas piping or eqfiipment upstream of the caustic scrubber,
the most serious release would occur during fluorination when fission-
product voletilization is expested to be greater and processing times
shorter than during the Hp-HF treatment. If the activity is evolved uni-
formly over a 10-hr period, 2% of the activity will be in the gas space
at any one time. If shutdown requires 6 min, another 1% would be evolved
for a total of 3%. Assumlng 90 days decay and complete volatilization of

tellurlum, the exposure at the p01nt of’max1mmm.ground concentration would

.~ be less than 3% of the permlsS1ble quarterly exposure. Ruthenlum.and

niobium releases would be of the same order if the releases occurred up-

“stream of the NaF trap (because of lower volatlllzatlon) and would be

much’ lower. downstream.of the NaF trap, which will provzde con31derab1e

:decontamlnatlon for these. activ1t1es.. These exposures are. conservatlve,
, &81nce much of ‘the act1V1ty*wou1d plate out or be removed by the filters.
ff:aThe leak.would ‘be: detected.by'both cell air monltors and fluorlde ion

' rmonltorsg and 1t seems reasonsble that fluorine flow could be stopped

o W1th1n 6 min.

The causes of an equlpment fallure that have been,cons1dered are

'corros1on and cr1t1ca11ty., Although corrosion rates as hlgh as 0.5

"'mll/hr durlng fluorination are expected, the fluorination tlme will be

short and processing will be infrequent, so the total corr051on‘W1ll be
small. Also, corrosion would probably not result in a complete rupture.

 
 

&4

A criticality incident is conceivable only if there is a large break-
| through of UFg to the caustic scrubber. The NaF trap and the absorbers
are critically safe without internal moderation because of the maximum

- cgpacity of 0.9 g of uranium per gram of NaF. Fluorination will be stopped
when uranium starts to load the final absorber, which will serve as a trap
- to retain any traces of uranium passing the other absorbers. Since absorp-
tion will be very rapid and complete, there will be no possibility of
breakthrough of more than 1 or 2 g of uranium. Loading of the final ab-
sorber will bé detectable by temperature rise. The fuel storage tank off-
gas stream will pass directly from the NaF trap to the caustic scrubber
during Ho-HF treatment when no uranium is being volatilized. This will
require two physical changes in the piping to bypass the absorber train
and connect the gas supply line to HF instead of' Fas Administrative con-
trol of these piping changes will guarantee that fluorine cannot be used -
when the absorbers are not in the system.

4.3.2 Activity Release to the Opei'ating Area

The high-bay area above the f‘uel-processing cell will be used for
operation of the fuel-processing system. The possible release of gaseous
activity into this area during f‘uél processing through the roof plugs,
from the absorber cubicle, from the salt sampler, and from 1ines penetrat-
ing the cell walls was considered. As in Section 4.3.1, the most serious
release would be the release of tellurium during fluorination.

4.3.2.1 Activity Released Through the Roof Plugs. Leakage of ac-
tivity from the fuel-processing cell to the operating area is not con-
sidered credible for the following reasons:.

1. The cell is tightly sealed. All penetrations, piping, and wiring
are grouted and sealed with mastic or pass through sealed boxes. The roof
| plugs are gasketed at the bearing surfaces, and the joints are caulked.

2. A negative pressure of 1 in. of water will be maintained during
processing. This pressure should be easily attainable considering the
size and tightness of the cell. Air inleakage should be less than 500
£t /min by comparison with & Volatility Pilot Plant cell 50% larger and
having considerably more penetrations and maintaining a 2-in. negative

"

"

 
 

 

"

65

pressure with 300 to 500 ft3/m1n 1n1eakage. The nominal exhaust from.

the processing cell will be 500 ft?/min, with 50 to 100 ftB/mln of air

-entering the cell from the absorber cubicle during fluorination.

"3~_ Processing can be qulckly stopped. This would be done auto-

‘matically in case of a power failure, whlch would close the shutoff

valve on the gas supply (Fg,,HF, and Hy). The power failure would also
stop the flow of cooling air to the cubicle. This air exhausts to the
cell and is the only positive gas flow to the cell. A loss of ventila-
tion not caused'by'a.generalfpower failure is highly;improbable,since
there is & spare stack fan and the fans can be run with diesel power.

- If the cell should lose its negative pressure, an alarmfiwould sound and

processing could be Quickly suspended at the instrument panel board by
shutting off the main helium purge, which automatically closes the gas

flsupply-shutoff valve, and closing;the cooling air valve to the absorbers.

4.3.2.2 Activity Released from the Absorber Cubicle. The absorber
cubicle is a. sealed bdx-offiB/lfi-ifi.-thick steel located nmear the instru-
ment panel board in the high-bay area. It is located in the high-bay -
area to facilitate handling of the portable absorbers following fluorine-

tion. By means of the cubicle blower, the cubicle will be maintained at

‘a negative pressure with respect to the cell, which will be negative to

the high-bay area. Failure of power to the blower will cloSe the solenoid
valve in the air supply to'the'cubicle to avoid pressurization.

- The maximum cubicle pressure w1th lOO-ft3/m1n air flow will be checked

f to demonstrate'that a pressure greater than 1 p31g cannot be. Obtalned'W1th
- {the ‘blower off. If necessary the maxlmum.alr flow;w;llrbe reduced below
. 100 ft3/m1n to prevent exceedlng 1 psig. Prior'to'fluorination'the~vent
-velve will be closed, the cublcle pressure will be- ralsed to l psig, and |
the leak rate will be determlned., Leakage must,be.less than,l%/hr (220
"cc/mln) This rate of tellurlum.leakage would allow 14 min of'worklng
time in the high-bay area w1thout ‘masks. This is suff1c1ent time to shut
7:‘down and to evacuate the hlghpbay area, since the reactor w111 not be op-

eratlng durlng fuel proces51ng.a:r ' _
. The presence ‘of gaseous act1V1ty in the dbsorber cublcle w111 be de-
tected by a monitor that will be continuously sampling the cubicle air

during processing. If a leak occurs, processing can be suspended. The

 
 

 

66

cubicle will then be purged with air to the cell, the cubicle top will be

removed, ‘and ell joints will be checked for tightness. ©Smears from each
joint should indicate the location of the leak. '
4.3.2.3 Activity Released from the Cell Penetrations. All cell

'penetrations connected directly to process equipment are provided with

check valves, most of which are located in a sealed instrument cubicle
along with the instrument tranémitters. A backup of activity to the
check valves would be detected by a radiation monitor in the cubicle and
possibly by the area monitors in the high-bay area. o

Iti addition to the lines routed through the instrument cubicle,
there are three other penetrations from the cell to the high-bay area:
the salt sampler, which is discussed in the next section, the salt-
charging line, and the caustic-charging line. The salt-charging line
will be -séaled with at least one freeze valve and capped when not charg-
ing salt. The caustic-charging line to the caustic scrubber is provided

with a check velve and a manual valve. Caustic will not be charged dur-

ing processing, which would be the only time that pressure or activity
could be found in the charging line. ' |

The waste-salt line to the spare cell will be sealed by a freeze
valve in the processing cell. The method of waste-salt disposal has not
yet been determined.

4.3.2.4 Activity Released from the Salt Sampler. The fuel-process-

ing system sampler, as mentioned in Section 3.4.6, is similar to the fuel-

pump sampler-enricher. Both samplers have similar instrumentation and
will be used with similar operating procedures. The fuel-storage tank
will not be sampled during processing. Before sampling, the sampling
line and fuel storage tank will be purged of gaseous activity. The sam-
ple capsule containing the solid sample will be moved from the primary
containment area IC (see Fig. 3.13) to a secondary containment area 3A,

- where the sample will be sealed inside a transport container tube before

‘being removed from the sampler to a shielded carrier.

L4

 
 

n

»n

»

C

67

 

4.4 -Penetrating Radiation

4 4, 1 ‘Normal Levels

4.4.1.1 ggeratlgfi Area. The radiation level in the high-bay area
over the fuel-processing cell will be less thenelO_mr/hrrthrough,the e

_ft—thick‘high—density-concrete roof plugs under the most severe conditions

with & fully irradiated, four-day-decayed fuel salt batch in the fuel
storage tank. Since processing would not be started until the batch had
decayed for at least a few weeks, this level above the cell should cause
no concern. Opergtions will be planned to limit exposure of individuals
to less than 100 mr/week, and signs will be posfed indieeting radiation

“levels at various points in the high-bay area.

The salt sampler will be shielded with 4 in. of lead, which should
reduce the radistion level from a fuel salt sample to less than 10 mr/hr.

It will probebly'be neceSsary_to shield the absorber cubicle during
processing of a fully irradieted fuel batch. As mentioned in Section
2.2.4, the maximum radiatiohelevel expected at the surface of each ab-
sorber is less than 100 mr/hr. In addition there will be some activity

- plated out on the piping and some gaseous activity in the lines and gas

space during processing. The radistion levels will be monitored during

- processing, shielding will be added, and radiation signs will be posted

as required. Permanent shielding will not be installed, since it should
not be required during the morefifrequent Hp -HF treatment. .

4 4.1.2 Switch House.; The'only fuel-proeessing cell wall adjacent
to an: occupled ares - is the'west wall borderlng the switch house. The 4-

" ft area between the sw1tch house and the cell will be fllled.W1th stacked
“Tconcrete ‘blocks. ‘When & fully 1rrad1ated fuel batch 13 in the storage
:;tank, ‘the level at the: east wall of ‘the sw1tch house should be less than

5 mr/hr.

“4.4.1.3 Spare Cell. The:east”fiell:of'the fuelfproeeésing cell ad-

e501ns the spare: cell where thelactivatedrcharcdal trdp, fo-gas filters,

dampers, differentlal-pressure transmltter, and hydrogen flame arrester

are located. A blanked waste salt line extends into.this cell for future

removal of waste salt. Two feet of space is provided between the cell

 
 

 

68

wall and the above equipment for the installation of shielding blocks.
This space will provide for sufficient shielding (a total of 3 1/2 ft)
to permit replacing the off-gas filters without exceeding'plannéd expo?
sures. The dose rate should be less than 50 mr/hr.

4.4.1.4 Decontemination Cell. The 18-in. north wall of the fuel-
- processing cell borders the decontamination cell. Depending on the water
level, there will probably be a limited working time over the decontamina-
tion cell with the roof plugs off and a fully irradiated batch in the fuel
 storage tank. 3
4.4.1.5 Area Surrounding the Waste Cell. Thé maximum activity ex- - -

 

pected in the caustic solution from the fluorination of a 90-day~decayed
fuel batch is 1300 curies of tellurium, assuming 10% removel in the scrub-
ber. During the time this activity is in the liquid waste tank, there
must be limited access to the areas above and around the waste cell, and
radiation warning signs must be posted. '

4.4.2 Unusual Radiation Levels

 

4.4.2.) From Irradiasted Salt. There are two dip tubes in the fuel
storage tank into which salt could accidentally back up: the salt trans-
fer line and the gas-sparging line. The salt transfer line is connected
to the spare cell by the waste.salt line and to the high-bay area by the
'salt—charging line. Both lines have freeze valves that are normally
frozen. In addition, the end of each line will be capped when not in use.
The gas-sparging line passes through the area west of the cell to .
the instrument cubicle and then to the gas supply station. An air valve
located in the instrument'cflbicle opens if the tank pressure exceeds the -
purge pressure and vents the line to the top of the tank to prevent salt
backup. If a plug should occur, it could be thawed with installed elec-
tric heaters without entering the cell. o
4.4.2.2 From Caustic Solution. The greatest activity. expected in

 

the caustic scrubber tank is from tellurium. Under the reducing condi-
tions of the H:-HF treatment, very little of the tellurium'shéuld reach
- the scrubber. During fluorlhatlon most of the tellurium will probably
' volatlllze, but less than 10% is expected to collect in the caustic ‘ -

e

 
 

 

»

b

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69

 solution. In Volatility Pilot Plant run R-7, only 8% of the tellurium

was found in the scrubber, which is a much more efficient unit than the

- MSRE unit, which is designed primarily for the neutralization of HF.

If all the tellurium in a fully irradiated fuel salt batch allowed to
decay for 90.daySIwere;erlvéd during the first 8 hr.of fluorination
(first batch of caustic solution), and 10% were removed in the scrubber,

1300 curies would be collected in about 350 gal .of liquid. This is 3.7

curies/gal and could be sent to the intermediate level waste tanks at
the Central”Collection”Statibn without dilution after being jetted to
the MSRE liquid waste tank.

The solution could possibly get into unshielded lines in the follow-
ing ways: o | |

l. Pressuring of the scrubber tank during processing and plugging
of the vent line or flame arrester could force liquid up the jet suction
iine to the waste tank; which is the normal disposal route for caustic
solution and would create no hazard. Some solution might back up the jet
steam line, but this line is shielded to approximately 25 ft from the jet
and backup this far into a closed line is unlikely with an open line to
the waste tank. The pressure aiarmsron;both the fuel storage tank and
the caustic scrubber would provide sufficient warning to stop processing
before a dangerous pressure was reached.

2. Pressuring of thb scrubber tank during jetting plus plugging of
the vent line or flame arrester and plugging of the jet discharge line

- to the waste tank could cau3é7stéam.to back up through the caustic solu-

tlon. Con31derdble tlme would.be requlred to build up sufflclent pres-

sure (7 psig) to force solution up the sparge line to the absorber cubicle.

B Pressure alarms and radlatlon monltors would provide warning far in ad-

"rvance of any hazard.-

- 3. A vacuum 1n the Jet 1mne could pull solutlon into the steam llne.

_If the jet dlscharge llne Should plug and Jettlng should stop, conden31ng
_'steam could create such a vacunm. ‘A check valve tees 1nto the steam line
"and.w1ll prevent 8 vacuum.from formlng in this llne. ThlS check valve is

 yvented to the cell ventllatlon ‘system.

4. Cooling of the fuel storage tank w1thout gas purges to the tank
could cause a vacuum in the tank and off-gas piping to the scrubber. A

 
 

 

 

70

power failure could cause cooling of the tank but would not stop the he-
lium 'purges. In the event of a prolonged power failure and cooling of
the fuel storage tank, the caustic scrubber would be jetted to the waste
tank. ' | _

4.4.2.3 From Radioactive Gas. The sampling line is the only gas
line from the fuel storage tank to the operating area. Steps will be
teken as indicated in Section 4.3.2.4 to keep gaseous activity out of
‘the sampler. Sparging for 1 hr with helium should reduce. the activity
in the gas space by a factor of 10°. Complete filling of ‘the sampler
access chamber with atmosphere from the fuel storage tank wduld result
in a radiation level 10° times less than that from & fully irradiated
fuel selt sample. |

 
 

 

FFT
FI
FST

LIWT

- MVWS
PCV -
PAIAFPC
PIA

71

5. OPERATING PROCEDURES

Nomenclature

Fuel flush tank

Flow indicator

Fuel storage tank

‘Freeze valve ,

Remotely operated valve

Waste tank level indicator

Melton Valley waste station

Pressure control valve _
Fuel-processing cell differential-pressure indicator and alarm
Pressure indicator and alarm

Portable maintenance shield -

Pressure recorder and alarm

Valve

5.1 Hp-HF Treatment

5.1.1 System Leak Test

5.1.1.1 Close System

1. Freeze FV 110.
2. Freeze FVllll@” |
3. Freeze FV112. |
4. Close HCV 690;

5. C(Close HCV 692 _
6. ;Close v 994 and check buffer gas pressure.

See Section 4T of MSRE Operating
Procedures¥*

- 7. Check leak detector flanges on HCV 692, HCV 694, and NaF

: -'trap.”= -E?
8. Close v 607A.
9. Close v 608A.

10. Close V 610A. o

 

\./ | *¥Report ORNL-TM-908, Part VIIT of this series.

N

 
 

 

 

5.1.1.2

1.
2.
3.
4.
5.

8.

72

Apply Pressure and Test

Set PCV 530 to 20 psig.

Open HCV 530. N

When PRA 608 stops rising, close HCV 530.

Pressure should remain constant for 1 hr.

If pressure falls, do the following to find the leak:

&. Check end of line 692 in absorber éubicle for leaks.

b. Check purge connections in instrument cubicle for leaks.

c. Pressurize sampler-valve (V 994) buffer gas supply and
note effect on system pressure. _

When system is leak free, thaw FV-110 (see Section 4I¥)

and determine that'system.is still leak free. .

If system.leaks leak check flange on line lll and check
temperatures on FV 107, 108, and 109.
When system is leak-free, close HCV 530.

5.1.2 Absorber and Instrument Cubicle Preparation

5.1.2 .1

1.
2.
3.
4.

5.1.2.2

1.
2.

Prepare and Test Piping in Cubicle

Comnect line 692 to line 695 with ell.

Close V 693.

Install blind flange above V 693.

Check the two flanges in line 692 and one flange in line
693 with the "local leak detector." Tighten flanges as

required.
Leak Test Absorber Cubicle

Install gasketed cover on absorber cubicle.

Close V 978 and install pipe cap over valve stem.

Open V 970 and V 970B until pressure in cubicle reaches
27 in. H20. ' |
Adjust V 970B to 220 cc/min.

Pressure in cubicle should increase slowly. If this is
the case, close V 970 and stop the test when the cublcle

pressure reaches 30 in. HO.

kii,

 
 

 

 

E

5.1.2.3

5. l 3 System

5131,

73

If the pressure remains steady, check that the pressure
does not fall in 4 hr. '

If the pressure falls, check the tightness of the gasketed
cover, valve_eover,_and_valves to the radiation monitor.
If the pressure still falls, socap test all joints until
the leaks are found. ‘Build pressure back up to 30 in. if

necessary.
Leak Test Instrument Cubicle

Install gasketed cover on instrument cubicle.

Make temporary_tubiug connection from the outlet of FI 970
to the test tap on the cubicle cover.

Close V 979. ,

Open V 970B until pressure in cubicle reaches 27 in. Hz0.
Adjust V 970B to 150 cc/mln |

Pressure in cublcle, as read on PdIAFPC, should increase
slowly. If thls 1s the case, close V 97OB and stop the
test when the cublcle pressure reaches 30 in. HyO.

If the pressure remalns steady, check that the pressure
does not fall in 4 hr.

"If therpressure falls, soap test the cover and all penetra-

tions to the cubicle.

Preparation S

Charge Caustlc Scrubber

 Add 89 gal of'water to the lOO—gal makeup tank.
Add 25.3 gal of 45% KDH from.a 55- gal drum to the makeup

tank o -
Mix w1th agltator for 10 min.
Connect tank to 11ne 313

Open V 313 and ta.nk draln valve.
Close valves and repeat steps l to 3 two tlmes for a total

addition of 343 gal of caustic.

 
 

 

. 5-1-3-2

1.
2.
3.

2.1.3.3

2,

5.103.7

T4

Purge FST and Gas Piping

Open HCV 692.
Open V 607A and set flow at 100 liters/min.
When system has been purged for 2 hr, close V 607A.

Transfer Salt Batch to FST

Thaw FV 110 (see Section 4I%).
Transfer salt batch (see Section 11A¥).

Adjust Purge Gas Flows

 

Open V 607A and purge at 1 liter/min.
Open V 608A and purge at 5 liters/min.

Adjust Temperatures

Adjust FST lower half temperatures to 1112 + 20°F.

Adjust temperature of lines 601, 692, 694, 695, and 9% to
200 to 250°F.

Adjust temperature of NaF trap to 750 + 20°F.

Upper half heaters of FST should be off unless needed to
maintain bottqmrtemperature.

Top heaters of FST should be turned on if necessary to keep
temperature at line penetrations above 200°F.

Check Instrumentation

 

Flow indicator alarm and radiation mbnitors in off-gas
stream should be in operation. ' )
Absorber and instrument cubicle radiation monitors should

be in operation..
Start Up Cold Trap System

Turn on the refrigeration unit.
Start brine recirculation pump. 7 |
Adjust_temperature of brine to maintain the specified tem-~

perafure at the outlet of the cold trap.

O

u;

9

 
 

»

75

5.1.4 Treatment

5.1.4.1

Sgggle Salt., The procedures for the fuel-pump sampler-

enr1cher*w111 be modlfled for thls sampler. See Section 6A of MSRE Op-

eretlng Procedures.

5.1.4.2

1.

2.

5,1.4.3

1.
2.

5.
line 842 and adgust to. malntaln scrubber temperature below
120 F.__Tijr | |

Start Gas Flows-

Connect Ng cylinders to N»-SOz- manlfold and start Ny purge
through F» disposal system at 5 liters/min.

Place 100-1b HF cylinder in water bath and comnect to line
697. Wear face shield, rubber gloves, and apron.

Open steam‘valve to water bath and adjust temperature con-
troller to'100°F. HF cylinder must not be heated above
122°F, which is equivalent to the PIA set point of 25 psig.
Twrn on HF heater and adjust to 180 to 200°F.

Connect Hz cyllnders to manifold and adgust flow to 91
llters/mln.

Set FIC 696 at 9 liters/min. Check that HF temperature

at flowmeter is 180°F. Water bath temperature controller
can be'raised'fo a maximum of 122°F if necessary to obtain

the d351red flow rate.

Treat Salt s

Record all temperatures and adjust as required every 15 min.
Record all gas flows and ‘adjust as requlred every 15 mln.

When scruhber tem@erature beglns to rlse, turn water on |

Record cold trep outlet temperature every 15 mln.rr
Check thet srphon pot discharge line temperature is being
recorded and each dlscharge is recorded. Frequency of dls-_'

chargeS'W1ll decrease as treatment progresses. :

~ When molarlty of. caustlc calculated from HF consumptlon

falls to 0. 35, stop HQ and HF flows, Jet caustlc to waste,
charge fresh caustlc, and resume treatment. A caustlc
batch should last for at least four days. The HF cylinder

 
 

9.

5-104.4

5.1.4.5

76

will also last for approximately four days, so these can
both be changed at the same shutdown. |

When the time between siphons is greater than 1 hr (oxide
removal rate less than 2 ppm/hr), heat the upper half and
top of the FST to 1000°F.

If the siphon rate does not increase in the nékt hbur, turn

off the HF flow. _ i
Stop the brine circulation pump and turn off the refrigera-

tion wnit.

Tron Reduction

Raise the temperature at the bottom of the FST to 1300 * 20°F.

Continue the Hp flow at the normal rate (91 liters/min).
Sample salt every 8»hr untilZSample_analyzes less than 10
ppm iron.

Stop Ho flow.

Close V 698C in nitrogen line.

Open V 698D and increase nitrogen flow to 50 liters/min.
Again raise temperature of the upper half and top of the
FST to 1000°F.

After 8 hr, stop the nitrogen flow.

Take final salt samples.

Shutdown System

Turn heat off lines 691, 692, 694, 695, and 99%.

Turn off water to line 842. ;' |

Jet caustic solution to waste tank.

Turn off steam to HF cylinder heater and disconnect cylinder.
Turn off heat to HF gas heater. |
Turn off Hz flow and disconnect cyllnder

Turn heat off NaF trap.

 
 

b

o

iy

5.1.5 Liquid Waste Disposal

 

5.1.5.1

1.

5.1.5.3

Radiation Level Mbnltorlng .

Monitor radlatlon levels at west and north walls and above

liquid waste-cell as ‘soon as caustic batch has been Jetted

+ to the waste tank.

Post rediation level’ 31gns if level exceeds 3 mmem/hr.

Liguid Waste: Sampllng

_Close vV 302.

Close V 303B.
Close V 305A.
Close V'305B.,
Open V 30L.

Open V 300.
Start waste pump and c1rcu1ate waste solutlon for 1 hr.

Check radlatlon level at waste pump' if level does not
exceed 100 mrem/hr take two 5-ml samples by carefully open-
ing V‘305B. ThlS must be done with HEalth Phy31cs surveil-
lance when act1v1ty is present.

If waste solution is ac1d1c, calculate required caustic

solution and neutralize with caustic throfigh line 313.

Liquid Waste Dilution. If activity level is greater than

 

10 curles/gal, water must be added to the liguid waste tank to reduce the
1_act1v1ty to thls 1evel., If the act1v1ty level is too great to permit
 7samp11ng, dllute to 4000 gal. ‘This should be sufficient to bring the

- activity level well below 10 curles/gal for the expected act1v1t1es “from
';‘a fully irradiated. fuel,batch decayed for 90 days._;;iig;':

VVStop waste pump
inpen V 306A

Open V 307.__ "'L‘

' 01ose VBOO.__.

Close V 306B.
Record waste tank level on LIWT.

 
 

5.2.1

5.1.5.4

1.

10.
11.

78

Open V 819A and V 819B.
When LIWT indicates that the required amount of water has
been added, close V 8194 and V 819B.

Transfer to Melton Valley Waste Station

Contact the Operations Division Waste Disposal Operator
and get approval for the waste transfer. Do not proceed
until approval has been obtained.

Open V 305A. -

Close V 301.

Close V 307.

Open V -300.

Start waste pump. Health physics 'personnel should be on
hand during this transfef. Area ebove and a.rdund waste
pump cell should be checked for unusual radiation levels.
Continue pumping until LIWT indicates the tank is empty
and the discharge pressure on the pump reads approximately
ZEero. o ) o

If necessary to flush the l:Lne to the MVWS this can be
done by opening V 303A and V 303B.

Stop the waste pump.

Close V 305A.

Close V 300.

5.2 Uranium Recovery

System Leak Test

5.2.1.1 Close System

1.
2.

Freeze FV 110.
Freeze FV 111.
Freeze FV 112.
Close HCV 690.
Close HCV 692.
Close V 994 and check buffer gas supply. v

See Section 4TI of MSRE Operating
Procedures™*

PR s

 

S —————
 

 

79

7. Check leak detector flanges on HCV 692, HCV 694, and NaF
trap and tlghten if requlred. |
‘8. Close v 60’7A. -
9. Close V 608A.
10. Close V. 610A.

5.2.1.2 Apply Pressure and Test

1. Set PCV 530 to 20 psig.
2. Open HCV 530.
3. When PRA 608 stops rising, close HCV 530.
4. Pressure should remain constant for 1 hr.
5. If pressure. falls, do the following to find the leak:
a,V‘Check end of line 692 in absorber cublcle.
. 'Check purge connectlons 1n 1nstrument cubicle.
Ce. Pressurlze sampler-valve buffer gas supply and note
effect on system.pressure. '
6. When system is leak free, thaw FVhllO and determlne that
_____ system is still leak free.,_
7. If system 1eaks, check flange on line 111 and FV 107, 108,
. and 109. o -
- 8. When system.iseleak'free, eleseHCV 530;_

5.2. 2 Absorber and Instrument Cubicle Preparatlon '
5 2 2 1 Install Absorbers:'tt -

~1. 'Pretreat 70 to 120 kg of NaF pellets by heatlng to 750°F

o for 1 hr w1th N: purge. Use portable salt- charglng furnace.
2. TLoad each absorber with 14 to 24 kg of NaF pellets, depend—
~ ing on type salt ‘being processed. -

f3.“ Install absorbers 1n absorber contalners 1n cublcle.

4. 'Cheek air flow to each absorber. e |
5g'rInsert thermocouple 1n each absorber. ”f;l

.ffiésfeConnect jumpers and plplng to absorbers.h-

7. Blank flange on line 695. _ |

8. Connect heaters and check 1nsulat10n on plplng in cubicle.

9. Turn on heat and check heaters and thermocouples.

 
 

 

 

 

 

5.2.2.2

5.2.3 System
5.2.3.1

1.
2.

3.

80

Leak Test Absorber Plplng

Check all flanges in cublcle'W1th "local leak detector.”
Close V 693.

Open HCV 692.

Set PCV 530 to 20 psig.

Open HCV 530.

When PRA 608 stops rising, close HCV 530.

Pressure should remain constant for 1 hr.

If pressure falls, soap check all joints.

Open V 693. B

Leak Test Absorber Cubicie

i Install‘gasketed cover on dbsorber cubicle.

Close V 978 and install pipe cap over valve stem.

Open V 970 and V 970B until pressure in cubicle reaches

27 in. Hz0. |

Adjust V 970B to 200 cc/min.

Pressure in cubicle should increase slowly. If this is
the case, close V 970 and stop the test when the cubicle
pressure reaches 30 in. HzO0.

If the pressure remains steady, check that pressure does
not fall in 4 hr.

If the pressure falls, check the tlghtness of the gasketed
cover, valve cover, and valves to the radiation monitor.
If the pressure still falls, soap test all joints until the
leaks are found. Build pressure back up to 30 in. if nec-

essary.

Preparation

Charge Caustic Scrubber

Add 89 gal 6ffwater,to the 100-gal makeup!tank.,

Add 25.3 gal of 45% KOH from a 55-gal drum to the makeup
tank. | | |

Mix with agitator for 10 min.

O

“W

 
 

[

5.2.3.6

S 1.

81

Comnect tank to=1ine 2313,

. Open V 313 and tank draln valve.

Close valves and repeat steps 1 to 3 two trmes for a total

of 343 gal of caustlc._ 7

Purge FST and Gas Plplng

- Open HCV 692.
‘Open V'607A and set flow at 100 llters/mln.
" When system.has been purged for 2 hr, close V 607A.

.3. e_Transfer Salt,Bateh to FST (omlt if fluorlne eondltloning)

Thasw FV 110 (see Section 4I%), |
Transfer salt batch (see Section 11A%).

Adjust Purge Gas Flows

 Open V 607A and set flow at 1 liter/min.

Open V 608A and set flow at 5 liters/min.

Adgust Te_peratures (omlt 1f fluorlne condltlonlng)

~ Adjust FST bottom temperatures to 835 20°F (900 20°F
“if the salt is flush_salt).

Adjust HF trap inlet temperature to 212°F and ‘exit to 80°F.

' Adjust temperature of lines 691, 692, 6%, and 994 and lines

in absorber cublcle to 200 to 250°F.

~ Adjust. temperature of NaF trap to 750 + 20°F. -
- Upper half heaters of FST should.be off unless needed to

malntain bottom temperatures., e

" Top’ heaters on FST should be turned on- 1f necessary to keep
, temperature at 11ne penetratlons above 200 F.._

Check Instrumentatlon

Radlatlon monltors in: off~gas- stream should be in operatlon.

'Absorber and 1nstrument cubicle radaatlon monltors should be

‘in Operation._;;fa o

 
 

 

82

Prepare Fluorine Disposal System -

Turn heat on SOz and Fé preheaters and adaust to 400°F.
Open steam valve to s reactor.
Connect four S0, cyllnders to manifold.

5.2.4 Fluorine Conditioning

The system must be treated with fluorine before fluorifiation and

before the system is radioactive. The purpose is to prevent fluorine

from contactlng grease and cau31ng a lesk durlng proce831ng. If radio-

active salt is to be treated with H:-HF before fluorlnatlon, the system

- should be conditioned prior to that treatment. The fluorine disposal

system will also be checked out at this time.

5.2.4.1

1.

Sample Caustic Solutibn B

Disconnect Monel liguid level tube west of cell and make
temporary connection to vacuum pump through large sample
bottle (~500 cc).

Start pump and pull approximately 100 cc of KOH into bottle.
Stop pump and recomnnect line to level instrument.

Adjust Temperatures

Adjust FST heaters to 200 to 250°F at all FST temperature-
measuring points.

Adjust HF trap inlet temperature to 212°F and exit to 80°F.
Adjust temperature of lines 691, 692, 694, and 994 and lines
in absorber cubicle to 200 to 250°F.

Adjust temperature of NaF trap to 200 to 250°F.

Start S0, Flow
Open V 698A and set PCV 698 to 20 psig.

Open V 698C and adjust V 698B to flow rate of 6.6 liters/min

(5% excess). ; o |
Check 502 preheater temperature and maintain at 400°F.

O

 
 

 

7

5.2.4.5

L
2«'

83

Start Fluorine and Helium Flows

Connect fluorine trailer.

Open fluorine trailer valves.

Adjust V 607B for helium flow rate of 13.75 liters/min.

V 608B is still adjusted for 5 liters/min.

Open V 690A and V 690B. Adjust PCV 690 for fluorine flow
of 6.25 liters/mln. | )

Check fluorlne preheater temperature and maintain at 400°F.
Adjust steam flow to fluorine reactor if necessary to keep
temperature below 1000°F.

Continue flow for 8 hr, and sample caustic solution (see
Sect. 5.2-4.%)57 Analyze for Ff,-SOZ -,7and KOH molarity.
Increase Fluorine Concentration to 50%

Adjust V 607B for helium flow rate of 7.5 liters/min.
Adjust V 698B for S0, flow rate of 13. 2 liters/min.

Adjust PCV 690 for fluorine flow rate of 12.5 llters/mln

Maintain preheater temperatures\at 400°F.
Continue flow for 8 hr, and sample caustic solution.

Increase Fluorine Concentration to 75%

Adjust V 607B for helium flow rate of 1.25 liters/min.

Adjust V 6983 for 302 flow rate of 19.7 l1ters/m1n.
Adjust PCV 690 for fluorlne flow rate of 18.75 11ters/m1n

- Maintain preheater temperatures at 4OO°F.7 S
| Contlnue flow:for=8 hr and.sample,caustlc-solution.

Increase Fluorlne Concentratlon to 100%

Adjust v 607B and V 608B for hellum flow rates- of 1 llter/mln

B each.

A

5.
6.

Adaust V 6983 for SOg flow rate of 52 25 11ters/m1n
Adaust PCV 690 for fluorine flow rate of 50 11ters/m1n.
Nhlntaln preheater temperatures at 400 F.

Continue flow for 4 hr and sample caustic solutlon.
Adjust V 698B for SO, flow rate of 100 liters/min.

 
 

 

84

Adjust PCV 690 for fluorine flow rate of 95 liters/min.
Maintain preheater temperatures at 400°F.
Continue flow for 4 hr, close V 690A, and sample caustic

solution.

Shutdown System

 

Adjust V 607B for helium flow rate of 50 liters/min.
Adjust V 608B for helium flow rate of 5 liters/min.
Continue S0, flow for 1 hr after increasing helium flows.
Close V 698A. n - |

Continue helium flows for one more hour.

Close V 607A and V 608A. o |

Close fluorine trailer“valves;f'

Disconnect fluorine trailer.

Jet caustic solution to liquid waste tank.

5.2.5 FPFluorination

5.2.5.1

1.
2.

Start Fluorine Flow

Connect fluorine trailer.

Open fluorine trailer wvalves.

Open V 690A and V 690B.

Set PCV 690 for flow rate of 100 liters/min.

Fluorinate

Start of UFg evolution is detected by a temperature rise

in the first absorber. At this time, do the following:

a. Open V 970 to cool first absorber. Keep temperature
as low as possible by increasing-air flow. Reduce
fluorine flow if temperature reaches 300°F.

b. Start S0z flow by opening V 6984, V 698B, and V 698C.
Adjust PCV 698 for flow of 50 liters/min. )

c. Check SO, and Fo preheater temperatures and maintain
at 400°F. | R

O

 
 

w

85

 Fluorine breakthrough is detected by a temperature rise in

the fluorine reactor. At this time, do the following:

a. Reduce fluorine flow rate to 50 liters/min.

b. Start helium flow to FST by opening V 607A and adjust-
ing V 607B to 50 liters/min.

c. Turnsfeem to fluorine reactor on full. Reduce pre-
heater temperatures slightly if necessary to keep re-
actor temperature below 1000°F.

Follow UFg absorption by absorber temperatures. As absorp-

tion starts_ln_second absorber, turn air on the second ab-

~ sorber and offrthe first absorber. Continue in this manner
‘until there is no heat of reaction in the absorbers. If
fuel containing'1ow-eflrichment uranium or thorium is being

processed, frve absorbers will not have sufficient capacity
for all the uranlumg and fluorlnatlon'W111 have to be sus-

pended to 1nsta11 new absorbers. When processing salt B

| ithls will not be necessary and steps {12) to (18) can be

- 10.
- 11 ‘»

eliminated. _
When the temperature starts to increase in the last absorber,
stop the fluorlne flow by closing PCV 690.

Adjust v 6OWB to 100 11ters/m1n hellum.sparge for 1 hr.

Then close V 6GZA. |
Close V 970 9’71, 9’72 973 and 9'74 to stop air flow to

the absorber cublcle.
‘Close v 698A to stop SOg flow.
-_After 15 mxn, check radlatlon monltors to see that there

°1s no leak 1nto the absofber cdblcle.. If act1V1ty is pres-

ent open v 970 and purge cublcle untll there is no air

activ1ty 1n the cublcle.

'-Close V’608A.::_;,; S B
,Turn off heat to llnes in cublcle._m

Remove absorbers (see Sect. 5.2.7).

, Install neW'absorbers (see Sect. 5.2. 2)

 
 

 

16.

86

Prepare system to resume fluorination (see Sect. 5.2.3).

Certain of these steps, such as transfer of salt, will not

- be necessary.

Resume fluorination (see Sects. 5.2.5.1 and 5.2.5.2).

When there is no more indication of absorber heating, stop

the fluorine flow by closing PCV 690.
Turn off S0, flow by closing V 69€A.

5.2.5.3 Sample Salt. Since a fluorine trailer will only last 2 hr

at 100 liters/min, it will be necessary to stop fluorination before all

the UFg is volatilized. The salt will be sampled every

2 hr while the

trailer is being changed'to'check on the progress of fluorination. At

alternate trailer changes (every 4 hr), it will be necessary to jet the

caustic solution to the waste tank and charge fresh caustic.

1.
2.

5.2.5.4

1.
2.
3.
4.

Close PCV 690.
Close V 690A and V 690B.

Adjust V 607B to 100 liters/min helium sparge for 1 hr.
Close V 607B and sample salt (see Section 6A of MSRE op-

erating procedures¥).

When uranium concentration is léss than 25 ppm, heat the
top half and top of the FST to 900°F and fluorinate for

an additional 30 min.

Stop fluorine flow and répeat helium,sparge for 1 hr and

resample.
If sample shows less than 15 ppm uranium,
is complete. 7

Check sample for free fluorine. Continfie

until below limit of detection.

Shutdown System

 

Close V 607A, 6084, and 609A.
Open V 312 and Jet caustic to waste tank.
Vent fluorine lines at trailer. =

Disconnect fluorine trailer and return to

the fluorination

helium sparge

K"25 .

Qii!

re,

O

 
S
6.

87

Disconnect 302 cylinders. _
Turn heat off lines 691 692 694 and 994 and lines in

absorber cubicle.

5.2.6 waste Salt Disposal

The method of dlsposal of waste salt has not yet been decided. This

procedure will be written some time in the future.

5.2.7 Absorber Removal

8.
7 _'9.

Check Cubicle

Check that there is no air activity as shown by air monitor.
Check gamma radiation at cubicle and get permissible working

time from health physics personnel.

- With health physics personnel present, remove cover from
cubicle. | o
~Check gamma radiation level at contact with absorbers.

Get alpha smears eroundeisconnect Joints.

.~ Remove Absorbers

 

Disconnect heaters.

Remove~thermoebuples.-

, Close HCV 692..

. Close V693, = . |

-flDlsconnect jumpers and llnes to absorbers.,f

V-Blank the flanges on absorbers and check*W1th “local leak

detector. oo

" Remove absorbers from absorber contalners and bag in plastic

after 8 smear test for alpha activity. R
If necessary clean out81de of absorbers‘befbre bagglng. '
Shlp absorbers to the Vblatlllty Pnlot Plant fbr uranium

recovery. o

 
 

 

88

5.2.8 Liquid Waste Disposal
5.2.8.1 Radiation Level Monitoring

1. Check radiation levels at west and north walls and above
liquid waste cell as soon as the caustic batch has been
jetted to the waste tank. -

'L2. Post radiation level signs where necessary.
5.2.8.2 Liquid Waste Sampling

1. Close vV 302.

2. Close V 303B.

3. Close V 305A.

4. Close V 305B.

5. Open V 301.

6. Open V 300. 7 o
7. Start waste pump and circulate waste fof'i hr.

8. Check radiation level at pump. If level is not too high
take two 5-ml samples by carefully opening V 305B. This
mist be done with health.phy31cs personnel survezllance
when activity is present.

9. If waste solution is acidiec, neutralize by adding the cal-

culated amount of caustic through line 313.

5.2.8.3 Liquid Waste Dilution. If activity level is greater than
10 curies/gal, add water to the liquid waste tank to reduce the activity
to this level. If the activity level is too great to permit sampling,
dilute to 4000 gal. This should be sufficient to bring the activity level
well below 10 cur1es/ga1 for the expected activities from a fully irradi-
ated fuel batch decayed for 90 days. ' '

1. Stop waste pump.
2. Open V 306A.
3. Open V 307.
4

Close V 300.
5. Close V 306B.
6. Record waste tank level on LIWT.

 
 

ey

89

 

 

7. Open V 819A and V 819B.
8. When LIWT 1nd1cates that the requlred amount of water has
. been added, close V 819A and V 819B.
5.2.8.4 Transfer to Melton Valley Waste Station -
l. Contact the'opefétions Division Waste Disposal Operator
| andTgétapproval for the waste transfer. Do not proceed
- until apfirOQéiihés been obtained.

2. Open V 305A.

3. Close V 30L.

4. Close V 307.

5. Open V 300, - | | -

6. Start waste pump. Health physics personnel should be on
hand during this transfer. Area above and around waste
pump cell should be-ghécked for unusual radiation levels.

7. Continue pumping until LIWT indicates the tank is empty
and the dis¢harge pressure bn the pump reads approximately
Zero. %i"” Lo - . _ '

8. If necessary to flush the line to the MVWS, this can be
done by opening V 303A and V 303B. -

9. Stop the waste pump.

10. Close V 305A.
11. Close V 300.
5.3 Equipment Decontamination
5.3.1 Summary

As mentioned in Sectlon 3. 2, the MSRE fuel-proce331ng system is de-

';fiSlgned for dlrect malntenance after decontamlnatlon, except for a few

_ 'remotely malntalnable 1tems, such as the two alr-operated valves and the

_ Decontamlnatlon‘w1ll con31st of-':

1.

2'

Flushing. of the salt llnes and.FST'W1th flush salt if the
lest operation was with fuel salt.
Displacing the salt in the freeze velves with clean salt.

T

 
 

 

 

 

 

90

3. Connecting salt line 112 to the caustic scrubber for liguid
waste disposal. ' ‘

4. Treatment of the salt system'with'ammonium.6xalate solution
for salt film removal. , - R

5. Treatment of the salt system'W1th n1tr1c ac1dralumanum
nitrate solution for metal fllm.removal._

6. Treatment of the gas system,with alkallne peroxlde tartrate

solution for decontamination.

Progress will be followed by liquid samples and radiation surveys
through the portable maintenance shield.

5.3.2 Preparation for Decontamination

5.3.2.1 Salt Flushing

1. Heat FST and salt lines to 1200°F.

2. Transfer flush salt batch to FST.

3. Transfer flush salt batch to FFT.. -

4. Charge can of flush salt (nat. Li) through line 111.
5. Connect waste salt can to line 112 in spare cell. |
6. Transfer salt from FST to waste salt can. -

5.3.2.2 Remove NaF Trap

 

1. Install PMS over plug No. 5. -

2. Disconnect pipe Jumpers, thermocouples, énd eiéétric leads
on NaF trap.

3. Remove NaF trap.

4. Install connecting jumper between upper flanges.

5.3.2.3 Radiation Survey

1. Check radiation levels through PMB w1th long handled prdbe.
Locate major sources of act1v1ty. ' '

2. Move PMS to plug No. 4 if necessary.
5.3.2.4 Liquid Waste Line

1. Remove can comnector from end of line 112 in spare cell.

2. Remove activated charcoal trap.

 
 

 

3.

4.

91

Connect line 112 to line 628 to caustlc scrubber with
temporary 1/2-in. Inconel pipe.
Blank line 628 to duct 940.

5.3.3 Oxalate Treatment

2.3.3.1

Oxalate Charging

Prepere Sevenfill5—gal batches of 0.5 M ammonium oxalate

solution in the caustic makeup tank.

" Heat FST and salt lines to 200°F.

Add exalate to FST through 11ne lll.

3.2 Qxalate Treatment

5.3.3. 3

Sparge FST with N» at 100 llters/mln for 4 hr.
Sample solutlon and check for gross gamma &Cthlty
(c¢/min-ml). e

Continue sparging for 4 hr more and sample.

- If there,;e.ncfiqppreC1eble increase in act1v1ty in the

sampleé7pres$uxe,eolution to caustic scrubber in three
1000-1iter batches and jet to the liquid waste tank.
If sample activity increases, continue sparging end sam-

pling untilzactivity levels off.

Radiation Survey. RepeatMradietidnUSfiffié& as in Section

 

5.2. 2 3 and compare readlngs. Ir salt system.has hlghest readings pro-

ceed to SeCtlon 5 3 5, lf gas system.has hlghest readlngs proceed to
._'Section 5 3 4.,, : N ,

115 3 4 Alkallne Peroxlde Tartrate Treatment

_5.3.4.1

_2,

Solutlon Charglng

Prepare six 115 gal 'ba,tches of 10wt % Na.OH—Q 5 wt % HgOg—ILO
wt % sodlum.tartrate in the caustic makeup tank. '

Connect, charging llne to flange upstream of V’693 in ab-

sofber cublcle and charge two batches to the caustic scrubber

at room temperature.

 
 

92

3. Change charging 1inefto line 695 and eharge't#o additional

~ batches. | | ‘

4. Jet solution to llquld waste tank.

5. Connect charging line to line 692 in absorber cubicle and
charge two batches. B - -

6. Pressure from FST to scrubber and. jet to waste tank.

' 5.3.4.2 Radiation Survey o

1. Repeat radlatlon survey as in Sectlon 5 2 2 3 to determine
the eff1c1ency of the tartrate treatment.
2. From readings de01de on repeatlng tartrate treatment or
using nitric ac1dralum1num.n1trate treatment of salt sys-
tem (Sect. 5.3.5).

5.3.5 Nitric Acid—Aluminum Nitrate Treatment

5.3.5.1 Solution Charging

 

1. Prepare seven 115-gal batches of 5 wt % HNOs—5 wt % A1(NO3)3
| solution in the caustic makeup tank.

2. Heat FST and salt lines to 200°F.

3. Add solution to FST through line 111.

5.3.5.2 Nitrate Treatment

 

1. Sparge FST with Ng at 100 llters/mln for 1 hr.

2. Sample solution and analyze for gross gamma. act1v1ty.

3. Continue sParglng and sampllng until act1v1ty 1evels ofT.
4. Pressure solution to caustic scrubber.

5. Neutralize with KOH.

6. Jet to waste tank.

5.3.5.3 Radiation Survey.,'Repeat radiation survey to determine the

need for continued decontamlnatlon and the maaor sources of activity.

 

“7 e |
i

 
 

ȴ

o

a4

93

‘References

Reactor Chemistry Division Annual Progress Report for Period Ending
Jan. 31, 1965, USAEC Report ORNL-~3789, Oa.k Ridge National Iaboratory
(in prepara.‘bn.on)

L. E. McNeese , An Experimental Study of Sorption of Uranium Hexafluo-
ride by Sodium Fluoride Pellets and a Mathematical Analysis of Dif-
fusion with Simultaneous Reaction, USAEC Report ORNL-3494, p. 82, Oak
Ridge National Laboratory, Novenber 1963.

R. L. Jolley et al., Equipment Decontamination Methods for the Fused
Salt~Fluoride Volatility Process, USAEC Report ORNL-2550, Oak Ridge
National Laboratory, August 1958.

Letter from J. H. Westsik to R. B. Briggs on Natural Convection Cool-
ing of MSRE Drain Tanks, May 21, 1962.

R. C. Robertson, MSRE Design and Operations Report, Part I, Descrip-
tion of Reactor Design, USAEC Report ORNL-TM-728, p. 244, Oak Ridge
National Laboratory, January 1965,

Letter from D. M. Davis to F. R. Bruce on Maximmum Values for Planned
Relea.ses of *3*1, May 19, 1964.

U.S. Department of Commerce Weather Bureau, Meteorology and Atomic

Energy, USAEC Report AECU-3066, July 1955.

F. A. Gifford, U.S. Weather Bureau, Oak Ridge, Tennessee, personal

‘commmication to L. A, Mann, Oak Ridge National Laboratory, Jan. 27,

1961.

 
 

 

95
ORNL~TM-907
. - Internsl Distribution
~1. R. K. Adams = . 47. T. L. Hudson
2. R. G. Affel 48. R. J. Kedl
3. G. W. Allin 49, S. 8. Kirslis
4, A. H. Anderson = = 50. D. J. Knowles
5. R. F. Apple 51. A. I. Krakoviak
6. C. F. Baes 52. J. W. Krewson
- 7. S. J. Ball ~ 53. C. E. Larson
8. S. E. Beall R 54. R. B. Lindauer
: 9. M. Bender ' 55, M., I. Lundin
. 10. E. S, Bettis 56. R. N. Lyon
11. F. F. Blankenship 57. H. G. MacPherson
12. R. Blumberg 58. C. D. Martin
13. A. L. Boch 59, H. C. McCurdy
14, E. G. Bohlmann 60. W. B. McDonald
15. C. J. Borkowski 61. H. F. McDuffie
16. H. R, Brashear 62. C. K. McGlothlan
17. R. B, Briggs 63. H. J. Metz
18. G. H. Burger - 64. A. J. Miller
19. J. A. Conlin 65. W. R. Mixon
20. W. H. Cook 66. R. L. Moore
2. L. T. Corbin - 67. H. R. Payne
22. W. B. Cottrell 68. A. M. Perry
23. J. L. Crowley 69. H. B. Piper
24. D. G. Davis 70. B. E. Prince
25. G. Dirian 71. J. L. Redford
26, S. J. Ditto 72. M. Richardson
27. F. A. Doss 73. H. C. Roller
28. J. R, Engel 74. M. W. Rosenthal
29. E. P. Epler 75. T. H. Row
: _ _ .~ 30. A.P. Fraas - - 76. H. W. Savage
o= L | 31, E.N.Fray . . 77. A. V. Savolainen
5 ’ .. . 32, H., A, Friedman - 78. D. Scott, Jr.
. : S | 33, C. H. Gebbard -~ -~ 79. J. H. Shaffer
- | L 34, M. J. Gaitanis 80. E. G. Silver
R - 35. R. B. Gallsher. - 81. M. J. Skinner
36, J. J. Geist S 82. T. F. Sliski
'37. W. R. Grimes 83. A. N. Smith
38. A. G. Grindell - 84. P, G. Smith
39. R. H., Guymon ~ 85. 1I. Spiewak
40, S. H. Hanaver -~ = 86. R. C. Steffy
41. P, H. Harley: 87. H. H. Stone
42. P. N. Haubenreich 88.- H. J. Stripling
43, G. M. Hebert ~ . 89, A. Taboada
44, P. G. Herndon -~ ~ = 90. :J. R. Tallackson
| 45. V. D, Holt 91. R. E. Thoma
./ , 46. A, Houtzeel 92. G. M. Tolson

 
 

 

- 93.
94.
95.
%.

98

112-113.
114~128.

D.
V.
B.

K.
J.

. Trauger
. Ulrich

. Webster
. Weinberg
. West

C. White

TRxHaw

96

99.

100.
101-102.
103-104.

-105-109.

110.

G. D. Whitman
H. D. Wills

Central Research Library

Y-12 Document Reference Section
Laboratory Records Department

Laboratory Records, RC

Extemal Distribution

Research and Development Division, AEC, ORO L
Reactor Division, AEC, ORO ’
Division of Technlca.l Information Extension, DTIE